Patent Publication Number: US-2022236032-A1

Title: Muzzle loader upper receiver for ar pattern rifle

Description:
CROSS-REFERENCE 
     This patent application claims priority to U.S. Provisional Application No. 63/140,510 filed Jan. 22, 2021, which provisional application is incorporated herein by specific reference in their entirety. 
    
    
     BACKGROUND 
     Field 
     The present disclosure relates to a muzzle loader AP pattern upper receiver that can be used to convert an AR rifle with an AR pattern lower receiver into a muzzle loader rifle. More particularly, the present disclosure relates to the components of the muzzle loader AR pattern receiver, which includes a muzzle loader barrel with a blast cap receiver and a bolt assembly coupled to the barrel that has a bolt configured for use with the muzzle loader barrel. 
     Description of Related Art 
     Often, rifle sportsmen enjoy shooting guns of different types and different calibers. However, one gun is often of a single type and of a single caliber. As such, the rifle sportsman has to obtain multiple guns in order to have different types and/or different calibers. While it may be favorable to have different types of guns, the rifle sportsman is forced into buying multiple guns. 
     Therefore, it would be advantageous to be able to have a gun that converts from a first type to a second type. 
     SUMMARY 
     In some embodiments, a muzzle loader AR rifle can include: an AR patterned muzzle loader upper receiver; a muzzle loader barrel coupled to the upper receiver; a bolt in the muzzle loader upper receiver; and an AR pattern lower receiver coupled to the muzzle loader upper receiver, wherein the lower receiver includes a trigger. 
     In some embodiments, a method of forming a muzzle loader AR rifle can include: providing an AR patterned muzzle loader upper receiver assembly of one of the embodiments; providing a standard AR patterned lower receiver assembly having a pivot pin and takedown pin; inserting the pivot pin into the pivot pin receiver hole; pivoting the muzzle loader upper receiver assembly at the pivot pin until the takedown pin is aligned with the takedown pin receiver hole; and inserting the takedown pin into the takedown pin receiver hole. 
     In some embodiments, a bolt can be configured for being included in a muzzle loader upper receiver, wherein the muzzle loader upper receiver is configured to be coupled to a AR pattern lower receiver assembly. The bolt can include a longitudinal axis and a longitudinal sequence comprising: a bolt tip; a cylindrical region; and a bolt end having a firing pin recess. In some aspects, the cylindrical region includes a cylindrical surface without any recesses. In some aspects, the cylindrical region is devoid of recesses or elevations between the front end and opener portion. In some aspects, an annular lip at the bolt tip includes an extractor in an extractor slot formed in the annular lip. In some aspects, a firing pin recess is included in the bolt and optionally a firing pin therein. 
     In some embodiments, a bolt can be configured for being included in an AR pattern muzzle loader upper receiver of an AR pattern muzzle loader upper receiver assembly. The muzzle loader upper receiver assembly can be configured to be coupled to a standard AR pattern lower receiver assembly. The bolt includes a unitary body as illustrated and described herein. 
     In some embodiments, an AR patterned muzzle loader upper receiver can be configured to be coupled with a standard AR patterned lower receiver. The AR patterned muzzle loader upper receiver can include a unitary receiver body having a receiver lumen. The unitary receiver body can include: a top; a proximal end having a bolt opening with the bolt of one of the embodiments located therein; and a distal end having a barrel opening. In some embodiments, a bottom of the receiver body can include: a magazine slot open to and longitudinally aligned with a hammer slot, the hammer slot being narrower than the magazine slot. However, some muzzle loader configurations can omit the magazine slot as there is magazine used in a muzzle loader. On the other hand, use of the AR patterned upper receiver described herein can be used for the muzzle loader configuration or the bolt action configuration of the incorporated references. 
     In some embodiments, a takedown pin receiver hole is at a proximal end, the takedown pin receiver hole being orthogonal with the magazine slot and hammer slot; and a pivot pin receiver hole at a distal end, the pivot pin receiver hole being orthogonal with the magazine slot and hammer slot, the pivot pin receiver hole being parallel with the takedown pin receiver hole. 
     In some embodiments, the receiver body can include a first side having: a bolt handle slot extending from the bolt opening; a bolt rest slot extending from the bolt handle slot. In some aspects, the receiver body can also include an ejection port between the bolt handle slot and distal end, which can allow for the same receiver body to be used for a bolt action receiver body and the muzzle loader receiving body (see the cross-referenced applications). The receiver body can also include a second side. 
     In some embodiments, an AR patterned muzzle loader upper receiver assembly can include: an AR patterned muzzle loader upper receiver configured to be coupled with a standard AR patterned lower receiver, wherein the muzzle loader upper receiver comprises a unitary receiver body having a receiver lumen. In some aspects, the unitary receiver body can have: a top; a proximal end having a bolt opening; a distal end having a barrel opening; a bottom, a first side and a second side. In some embodiments, the bottom can include: a magazine slot open to and longitudinally aligned with a hammer slot, wherein the hammer slot is narrower than the magazine slot. In some aspects, the magazine slot is omitted in a muzzle loader specific configuration of the unitary receiver body. The first side can have: a bolt handle slot extending from the bolt opening and exposing a portion of the receiver lumen; a bolt rest slot extending from the bolt handle slot; and an ejection port between the bolt handle slot and distal end. Additionally, the bolt of one of the embodiments can be slidably located in the receiver lumen. 
     In some embodiments, an AR patterned muzzle loader rifle can include: an AR patterned upper receiver; a muzzle loader barrel coupled to the upper receiver, wherein the muzzle loader barrel is configured as described herein; the bolt of one of the embodiments can be slidably located in the upper receiver; and an AR patterned lower receiver is coupled to the upper receiver, wherein the lower receiver includes a trigger and a magazine recess. 
     The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The foregoing and following information as well as other features of this disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several embodiments in accordance with the disclosure and are, therefore, not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings. 
         FIG. 1  illustrates a side view of an AR rifle (Prior Art). 
         FIG. 2A  illustrates a muzzle loader upper receiver assembly separate from a standard AR pattern lower receiver assembly. 
         FIG. 2B  illustrates a muzzle loader upper receiver assembly connected via a pivot pin to a standard AR pattern lower receiver assembly. 
         FIG. 2C  illustrates a muzzle loader upper receiver assembly connected via a pivot pin and takedown pin to a standard AR pattern lower receiver assembly. 
         FIG. 2D  illustrates a muzzle loader upper receiver with the barrel protector and the ramrod, where the muzzle loader upper receiver is connected to the standard AR pattern lower receiver to form the muzzle loader AR pattern rifle. 
         FIG. 2E  illustrates the muzzle loader barrel coupled to the muzzle loader receiver via a barrel coupling nut. 
         FIGS. 2F-2G  illustrate the muzzle barrel having the breach plug. 
         FIG. 2H  illustrates the muzzle barrel without the breach plug. 
         FIG. 2I  illustrates the barrel side of the breach plug. 
         FIG. 2J  illustrates the receiver side of the breach plug. 
         FIG. 3A  illustrates a standard AR upper receiver assembly (semi-auto or full auto) being pivotally removed from a standard AR lower receiver assembly with the takedown pin removed therefrom. 
         FIG. 3B  illustrates a standard a standard AR lower receiver assembly. 
         FIG. 4A  illustrates a muzzle loader bolt. 
         FIG. 4B  illustrates a back portion of the muzzle loader bolt. 
         FIGS. 5A to 5D  illustrate different views of an embodiment of a muzzle loader upper receiver configured to be coupled with a standard AR lower receiver assembly. 
         FIG. 6  illustrates a muzzle loader barrel. 
         FIGS. 7A-7E  illustrate different views of an embodiment of a muzzle loader bolt with reduced length. 
         FIGS. 8A and 8B  illustrate an embodiment of a muzzle loader upper receiver assembly coupled with a standard AR lower receiver assembly. 
         FIGS. 8C-8E  show the muzzle loader upper receiver having the bolt in sequentially rotated views. 
     
    
    
     The components of the figures are arranged in accordance with at least one of the embodiments described herein, and which arrangement may be modified in accordance with the disclosure provided herein by one of ordinary skill in the art. 
     DETAILED DESCRIPTION 
     In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are explicitly contemplated herein. 
     Generally, the present invention relates to an AR rifle, such as an AR-10 and/or AR-15 or other configured and modifiable rifle as described herein. Particularly, the invention relates to a DPMS LR-308 pattern (e.g., AR pattern) for an upper assembly and lower assembly of an AR pattern rifle; however, it should be recognized that any appropriately configured rifle (e.g., Armalite AR-10 pattern) that can have the upper assembly separable from the lower assembly in the manner described herein may be combined with the muzzle loader upper assembly of the present invention. Now, with the present invention that includes a muzzle loader upper assembly that can be fit onto and coupled with a lower assembly (e.g., unmodified lower assembly, such as a DPMS LR-308 pattern, or Armalite AR-10 pattern), an AR pattern rifle may be converted to a muzzle loader rifle by merely replacing any AR pattern upper assembly or standard semi-automatic AR pattern upper assembly with the AR pattern muzzle loader upper assembly as described herein. As such, reference herein to AR rifles applies equally to the AR-10 and/or AR-15 or other similar rifles. One of skill in the art can use the teachings related to the AR-10 muzzle loader upper assembly provided herein in order to prepare an AR-15 muzzle loader upper assembly or any other AR rifle having the same type of coupling and pattern. While the application teaches the DPMS LR-308 pattern, the teachings are also for an Armalite AR-10 pattern. 
     As used herein, the “AR” is intended to mean a rifle of the type of AR pattern platform rifles (e.g., ArmaLite rifle pattern) that are commonly known, which are “assault rifle” type and may be “automatic rifle” type or “semi-automatic rifle” type. Otherwise, the AR is as defined herein can include the coupling pattern with the pin hole placement and alignment, along with the magazine, and/or hammer alignments. Also, it should be understood that the AR may be of any manufacturer that makes an AR rifle as known and understood by one of ordinary skill in the art. It is well known that an AR rifle is a specific platform and type of rifle. 
     In one aspect, the subject matter described herein is related to a DPMS LR-308 pattern muzzle loader (ML) upper assembly, DPMS LR-308 pattern bolt action (BA) upper assembly DPMS LR-308 pattern semi-automatic (SA) upper assembly, DPMS LR-308 lower assembly, and DPMS AR-10 ML or DPMS AR-10 SA. The subject matter may also relate to AR-15s, SA upper assemblies thereof, bolt action (BA) upper assemblies thereof (See incorporated references for AR bolt action), and lower assemblies thereof, which may also be DPMS LR-308 patterned. Also, it may be an Armalite AR-10 pattern. 
     By way of example and background, a standard semi-automatic AR pattern rifle is shown in  FIG. 1 . In some instances, features of the standard semi-automatic AR pattern rifle can be included in the AR pattern muzzle loader upper assembly, such as the barrel, barrel nut, and other aspects of mounting the barrel to the upper assembly. Also, the firing pin of a standard semi-automatic upper assembly may be utilized in the muzzle loader upper assembly. The present invention provides a muzzle loader upper assembly that mounts to a standard AR pattern rifle lower assembly as described herein. In fact, the muzzle loader upper assembly is configured to be self-contained and attachable to the lower assembly by using the takedown pin (e.g., rear pin) and pivot pin (e.g., front pin). For example, removing the takedown pin and pivot pin from a standard semi-automatic AR rifle allows the standard semi-automatic upper assembly to be removed from the standard lower assembly, and then the muzzle loader upper assembly can be mounted onto the standard lower assembly with the takedown pin and pivot pin replaced in order to arrive at the fully functional muzzle loader AR rifle. 
       FIG. 1  shows an assembled AR-10.  FIG. 1  shows the semi-automatic upper assembly  1 A mounted to the standard lower assembly  101 A via the takedown pin  123  and pivot pin  120  being received through the proper holes in the upper assembly  1 A and lower assembly  101 A, such as described herein. It is noted that the takedown pin  123  and pivot pin  120  can be either of the pins labeled with  120  and  123 , which can be switched to which one is the takedown and which one is the pivot. 
     A standard automatic or semi-automatic AR-10 upper assembly  1 A often includes an upper receiver, charging handle assembly, bolt carrier assembly, barrel tube, slip ring retaining ring, slip ring spring assembly, barrel nut, slip ring, gas tube, handguard (barrel protector), handguard cap, picatinny gas block, picatinny housing clamp screw, gas tube pin, spiral pin, front sling swivel, crush washer, and flash suppressor. An upper pivot pin receiver hole  20  (e.g., for receiving the pivot pin  120 ) and an upper takedown pin receiver hole  22  (e.g., for receiving the takedown pin  123 ) are shown to receive pins (e.g., pivot pin  120  and takedown pin  123 ) from the lower assembly  101 A in order to form the full AR-10. Due to the pivot pin  120  and takedown pin  123  being installed in the upper pivot pin receiver hole  20  and upper takedown pin receiver hole  22 , respectively, the upper pivot pin receiver hole  20  and upper takedown pin receiver hole  22  are not clearly seen; however, they are shown in other figures provided herein. It should be noted that the elements  20  and  22  may be switched. 
     It should be noted that the barrel tube  4 , slip ring retaining ring  5 , slip ring spring assembly  6 , barrel nut  7 , and slip ring  8 , can, in some embodiments, be used to mount the barrel to the inventive muzzle loader upper assembly as described herein; however, some embodiments may omit these components. The hand guard  10  may also be used with the muzzle loader upper assembly; however, a modified hand guard with a ramrod slot (e.g., holding a muzzle loader ramrod shown in  FIG. 2D ) may be preferred. In other embodiments, an AR free float fore end can be included in the inventive muzzle loader upper assembly as described herein. 
     In some embodiments, a fore end having a gas block is excluded from the present invention. 
     An assembled muzzle loader AR having the muzzle loader upper assembly mounted to a lower assembly  101 A may be provided in an embodiment. The lower assembly  101 A can include the lower receiver  101 , buttstock assembly  102 , receiver extension tube, operating spring  104  ( FIG. 3B ), buffer  105 , buttstock spacer, buttstock screw, buffer detent, pistol grip  110 , pistol grip screw, pistol grip washer, bolt stop, bolt stop pin, bolt stop plunger, bolt stop spring, magazine catch, magazine catch button, magazine catch spring, pivot pin  120 , detent pin, detent spring, takedown pin  123 , safety selector, safety spring, safety detent, trigger pin, two stage tactical hammer, D-ring, hammer torsion spring, trigger spring, two stage trigger  132 , coiled spring pin, two stage disconnector, disconnector spring, trigger guard assembly  136 , and trigger guard pin, as known. Pivot pin receiver hole  138  is shown to receive the pivot pin  120  (e.g., difficult to see due to the pivot pin  120  being therein) and takedown pin receiver hole  139  is shown to receive the takedown pin  123  (e.g., difficult to see due to the takedown pin  123  being therein). The entirety of the lower receiver  101  and/or lower assembly  101 A may be used for the muzzle loader AR rifle described herein, where the entirety of the lower receiver assembly  101 A may be mounted to the muzzle loader upper receiver assembly. 
     To mount the upper assembly  1 A with the lower assembly  101 A, the upper pivot pin receiver hole  20  is aligned with the lower pivot pin receiver hole  138  with the pivot pin  120  being received therethrough, and the upper takedown pin receiver hole  22  is aligned with the lower takedown pin receiver hole  139  with the takedown pin  123  received therethrough, in any order and vice versa. Pulling out the takedown pin  123  and pivot pin  120  allows disassembly, and replacement of the takedown pin  123  and pivot pin  120  allows assembly, which can be done with either pin in any order. 
     The AR-10 can include a bolt carrier assembly having the firing pin retaining pin, firing pin, firing pin spring, cam pin, bold carrier, key screws, bold carrier key, and bolt assembly as separate parts, as known in an AR pattern rifle. Here, the firing pin, and firing pin spring can be used with the bolt of the muzzle loader upper assembly. 
     The AR-10 can include a bolt assembly having the gas ring, bolt, extractor spring insert, extractor spring, o-ring, extractor, extractor pin, ejector pin, ejector spring, and ejector. Here, the extractor spring insert, extractor spring, and extractor can be used in the muzzle loader bolt assembly described herein. Therefore, a standard AR rifle with a standard AR lower receiver we well described herein and generally known. 
       FIGS. 2A-2C  shows an AR-10 muzzle loader (AR-10 ML) upper assembly  300  separate from the lower assembly  101 A and then the coupling of the upper assembly  300  to the lower assembly  101 A in order to form the muzzle loader AR rifle  200  in  FIG. 2C .  FIG. 2C  shows the lower assembly  101 A with the pivot pin  120  and takedown pin  123  in the receiver holes to fasten the muzzle loader (ML) upper assembly  300  to the lower assembly  101 A, which is the assembled muzzle loader AR rifle  200 . 
       FIG. 2A  shows the upper assembly  300  separate from the lower assembly  101 A. It is noted that this lower assembly  101 A is the standard AR pattern lower assembly for the semi-automatic AR rifle.  FIG. 2B  shows the takedown pin  123  being removed from the upper takedown pin receiver hole  22  so that the back of the ML upper assembly  300  can pivot on the pivot pin  120  in the upper pivot pin receiver hole  20 . It is noted that the upper takedown pin receiver hole  22  is in a takedown receiver body, and the upper pivot pin receiver hole  20  is in a takedown pin receiver body. As shown, the takedown pin  123  and pivot pin  120  do not need to be pulled all the way out of the takedown pin receiver hole  139  and pivot pin receiver hole  138 , but only from the upper takedown pin receiver hole  22  and upper pivot pin receiver hole  20 . It is noted that either pin can be pulled out first for removal or inserted for assembly. 
     Performing the steps from  FIG. 2C to 2A  disassembles the AR-10 ML, and performing the steps from  FIG. 2A to 2C  assembles the AR-10 ML; however, either pin can be pulled first or assembled first. Also, it can be seen that the takedown pin receiver hole  139  is actually two different holes, one on each side of the lower assembly  101 A, and thereby the takedown pin  123  only needs to be withdrawn from one and from the upper takedown pin receiver hole  22 . Also, it can be seen that the pivot pin receiver hole  138  is actually two different holes, one on each side of the lower assembly  101 A, and thereby the pivot pin  120  only needs to be withdrawn from one and from the upper pivot pin receiver hole  20 . 
       FIG. 2D  show an embodiment of the muzzle loader AR rifle  200  ML with the ML upper assembly  300  coupled to the AR lower assembly  101 A. The barrel  4   a  is covered with a barrel protector  250 , which includes apertures and a picatinny rail. The barrel protector  250  can also include a ramrod slot  252  that is adapted to receive a ramrod  254  therein. A support member  256  can also be used to hold the ramrod closer to the muzzle end  604 . The  414  bolt handle and handle slot  412  of the receiver  402  of the ML upper assembly  300  are clearly shown. 
       FIG. 2E  shows the barrel coupling nut  420  holding the barrel  4   a  to the receiver  402 . The top right image shows the barrel  4   a  without the barrel coupling nut and showing the internal threading. 
       FIGS. 2F-2H  show the barrel  4   b  with the barrel coupling nut  420  removed. The barrel  4   b  has been machined to function similarly to a barrel extension nut, but no barrel extension nut is used. Instead, the barrel coupling nut  420  slides over the barrel  4   b  at the back end  602  opposite of the muzzle end  604 . The barrel  4   a  includes an annular ridge  606  a distance from the back end  602  as shown, where a cylindrical portion  608  extends from the annular ridge  606  to the back end  602 . Here, the annular ridge  606  is machined into the barrel  4   a,  which functions as the barrel extension nut. The back end  602  of the barrel  4   a  is threaded and a breach plug  610  is threadedly inserted therein. The breach plug  610  is threaded as shown, which matches the threading of the back end opening  603  of the back end  602 . 
       FIG. 2G  shows the breach plug  610  being withdrawn from the back end opening  603  of the back end  602 . 
       FIG. 2H  shows the back end opening  603  being empty. 
       FIGS. 2I and 2J  show the breach plug  610  with the powder side  612  and the primer side  614  adapted to hold the primer cap (e.g., also called a percussion cap on older muzzle loaders, such as side lock or other inline models). The powder side  612  is adapted to hold the powder or other charge material that causes the blast. The primer side  614  hold the primer cap that is stricken to cause the powder to ignite and fire the projectile out of the muzzle loader. The breach plug  610  includes a passageway between the powder side  612  and the primer side  614  so blast from the primer cap can ignite the powder on the powder side  612 . Therefore, the breach plug includes a powder side  612 , then the threading, then an annular collar  616 , then a nut portion  618 , and then the primer side  614  having the primer opening  618  for receiving the primer cap.  FIG. 2I  shows the barrel side that faces or inserts into the barrel and  FIG. 2J  shows the receiver side that faces inserts into the receiver. 
       FIG. 1  shows an AR-10 semi-automatic (AR-10 SA) with the pivot pin  120  and takedown pin  123  in the receiver holes to fasten the semi-automatic (SA) upper assembly  1 A to the lower assembly  101 A.  FIG. 3A  shows the takedown pin  123  removed from the upper assembly  1 A so that the SA upper assembly  1 A pivots on the pivot pin  120 .  FIG. 3B  shows the pivot pin  120  removed so that the SA upper assembly (not shown) is detached from the lower assembly  101 A. Optionally, the operating spring  104  can be removed or retained therein when the ML upper assembly  300  is mounted to the lower assembly. Performing the steps from  FIG. 1  then  FIG. 3A  to  FIG. 3B  disassembles the AR-10 SA, and performing the steps from  FIG. 3B  to  FIG. 3A  then to  FIG. 1  assembles the AR-10 SA.  FIG. 3B  shows the standard AR lower receiver alone. These steps can be followed with the muzzle loader upper receiver and standard AR lower receiver to form the muzzle loader AR rifle. 
     Accordingly, the present invention can include a ML upper assembly that mounts to a lower assembly to form an AR-10 ML rifle. The present invention can also include the AR-10 ML rifle having the ML upper assembly mounted to the standard AR lower assembly. The present invention can also include a kit including the standard AR lower assembly with the SA upper assembly and ML upper assembly. The present invention can also include a kit including the standard AR lower assembly with the SA upper assembly and ML upper assembly and bolt action (BA) upper assembly from the incorporated applications. 
     The present invention may also include a method of converting an AR-10 SA rifle into an AR-10 ML rifle. The present invention may also include a method of attaching a ML upper assembly to a lower assembly to form the AR-10 ML rifle. The present invention may also include a method of disassembling an AR-10 ML rifle into a ML upper assembly and a standard AR lower assembly. Other assemblies, guns, kits, systems, and methods of making/assembling or methods of disassembling are also included. The methods may include assembling and/or disassembling the ML upper assembly. The individual components of the ML upper assembly may also be embodiments of the invention. 
       FIG. 4A  shows the bolt  450 , which is adapted to include the firing pin (not shown) therein. The bolt  450  includes the bolt handle hole for coupling with the bolt handle  414 , and whereby the bolt handle hole is aligned with the bolt handle slot  412  when the bolt  450  is in the receiver  402 . 
     When included, the roll pin hole receives a roll pin (not shown), which holds the firing pin in. The firing pin is free floating. The firing pin can be any standard AR-10 firing pin. In one option, the firing pin can be a DPMS LR-308 AR firing pin, such as AR-10 (e.g., Armalite AR-10) or AR-15. 
     Opposite of the bolt tip  458  is a bolt end  480  that has a firing pin recess  482  for retaining the firing pin therein. The firing pin recess  482  at the bolt end  480  is next to an end ridge  484  with an end ramp  486 . The end ridge  484  and end ramp  486  allow for operation of the rifle by setting the hammer in a locked position. The end ridge  484  keeps the hammer set in the locked position while the bolt  450  is in the open position all of the way forward. The end ramp  486  is what pushes the hammer back down while pushing the hammer forward after firing the rifle so that the hammer can again rest on the end ridge  484  before closing the bolt  450 . 
     There is an end slot  488  at the firing pin recess  482  next to the end ramp  486 , where the end slot  488  has a dimension D from the end ridge  484  and/or end ramp  486  and a dimension D 1  from the end  480 . The dimension D is configured for hammer clearance in the end slot  488 . The dimension D 1  is from the end and allows for operation, with the end ridge  484  extending from the body  472  to make the end slot  488  shaped as shown. The end ridge  484  can keep the gun from shooting by keeping the hammer set in the locked position, but once the hammer is in the end slot  488 , the hammer can release. Thus, when the bolt  450  is open, the rifle can&#39;t shoot, but when the bolt  450  is closed the hammer is in the end slot  488  and the rifle is able to fire. 
     The AR has a swinging hammer that is received into the end slot  488 , and which strikes the firing pin within the bolt  450 . When the bolt  450  is drawn back, it pushes the hammer back, and the hammer pushing ridge (e.g., end ridge  484 ) sets the hammer 
     Also, the bolt  450   b  can be substantially a cylinder with or without any plane or flat portion  451  as shown herein. 
     In some embodiments, a version of the bolt can be configured with a breach plug. Another embodiment of the bolt can be configured to hold the primer cap itself so that the breach plug can be devoid of holding the primer cap, where the bolt provides the primer cap into the breach plug. 
     In some embodiments, a primer cap extraction tool can be provided that includes a recessed end adapted to hold a primer cap for insertion into the breach plug and a forked end adapted for removing a the primer cap from the breach plug. 
       FIG. 4B  shows that the tail end of the bolt  450  has the firing pin recess  482  and the end slot  488  at the firing pin recess  482  next to the end ramp  486 , where the end slot  488  has a dimension D from the end ridge  484  and/or end ramp  486  and a dimension D 1  from the end  482 . The firing pin recess  484  is recessed into the tail end  480  of the bolt  950 . The firing pin recess  484  also opens to the end slot  488 . This forms an L shaped planar tail surface  991  and cooperative L shaped opening from the firing pin recess  482  and end slot  488 . The firing pin recess and end slot  488  forming an L slot having an L shape defined by the L shaped planar tail surface  491 , along with the corresponding end ramp  486 . 
     There is an end slot  488  at the firing pin recess  482 , where the end slot  488  has a dimension D from the end ridge  484  and/or end ramp  486  to the hammer pushing ridge  490 . The dimension D is configured for hammer clearance in the end slot  488 . The hammer pushing ridge  490  can keep the gun from shooting by preventing the hammer from setting, but once the hammer is in the end slot  488 , the hammer can set. Thus, when the bolt  450  is open, the gun can&#39;t shoot, but when the bolt  450  is closed the hammer is in the end slot  488  and the gun is able to fire. 
     The AR has a swinging hammer that is received into the end slot  488 , and which strikes the firing pin within the bolt  450 . When the bolt  450  is drawn back, it pushes the hammer back, and the hammer pushing ridge  484  sets the hammer 
     The dimension D is important for hammer clearance. The dimension D can be about 1″, or +/−1%, 2%, 5%, or 10% for an AR-10; however, an AR-15 can have different values for the dimension D. When the bolt  450  is closed, it is in a position so that the hammer can swing the full length for firing the rifle. But when the bolt  450  is opened, the bolt holds the hammer so that it cannot strike the firing pin so that the rifle cannot fire. The hammer clearance D is dimensioned so that once the rifle has fired, you can still draw the bolt  4  back to get the hammer to cock again. 
     The end ramp  486  and end ridge  484  make sure that when the bolt  450  is not fully seated, the gun will not fire. While the hammer may be pulled forward, it is at an angle that does not hit the firing pin. When pushing the bolt  450  forward you can get to where the hammer is between the body and the end ramp  486 , you can pull the trigger and the hammer will go off, but it can&#39;t hit the firing pin because it&#39;s on the wrong angle. So the gun still can&#39;t go off. Even if you close the bolt  450  all the way with the hammer forward, the gun is not going to go off. The bolt  450  has to be rotated and seated so that the bolt handle is seated in the bolt rest in order for the gun to fire. As such, the bolt  450  provides safety mechanisms so that the gun does not fire until the bolt is set with the bolt handle in the bolt rest. 
       FIGS. 5A-5D  show different views of the upper receiver  402  of a ML upper assembly  300 , which is configured for muzzle loader firing.  FIG. 5A  shows a perspective view and  FIG. 5C  shows a bottom view of the upper receiver  402 . The bottom view of  FIG. 5C  shows that the same magazines of an AR-10 SA may fit into the ML upper assembly  300  and thereby the AR-10 ML; however the ML upper assembly  300  may be devoid of the magazine slot because the muzzle loader has no use of a magazine. However, the illustrated upper receiver  402  is also usable in a bolt action AR, such as described in the incorporated references.  FIG. 5D  shows the other side of the upper receiver  402 . This shows that the bolt action upper assembly of the incorporated applications can be used in the ML upper assembly  300 . Accordingly, some aspects include a kit with the upper receiver  402  along with the bolt action bolt and the muzzle loader bolt. The kit could also include the barrels and other components for both the bolt action AR and the muzzle loader AR. 
     The receiver  402  includes a threaded receiver  404  for receiving the barrel, which threaded receiver  404  is shown without threading. A barrel coupling nut  420  (see  FIGS. 2A-2D and 2E ) is provided for coupling the barrel  4   a  into the receiver  402  by screwing onto threaded receiver  404  (shown without threading). The barrel coupling nut  420  as shown in  FIG. 2E  is adapted to be received onto the threaded receiver  404 . The barrel  4   a  can be slid in and the barrel coupling nut  420  screwed into the receiver  402  to mount the barrel  4   a.    
       FIGS. 5A-5D  show a threaded relief  408  is behind the threaded receiver  404 . The threaded receiver  404  includes a dowel pin receiver  406  that is configured to receive a dowel pin, where the dowel pin keys into the dowel pin receiver  406 . The threaded receiver  404  is threaded the same as an AR upper receiver. The barrel  4   a  slides into the barrel coupling nut  420 , and then the barrel coupling nut  420  screws into the receiver  402  into a tight fitting. Optionally, the dowel pin hole of the barrel extension nut  420  aligns with the dowel pin receiver  406 , and then the dowel pin is received into the dowel pin hole and dowel pin receiver  406 . The barrel coupling nut  420  ( FIG. 2E ) goes over the barrel  4 A and tightens to the threaded receiver  404 , where the barrel coupling nut  420  is on the outside and locks down the barrel  4   a  to the receiver  402 . As such, the barrel  4   a  may be attached to the upper assembly  300  by sliding into the barrel coupling nut  420  that is then screwed to the receiver  402 . A barrel coupling nut  420  can be used to attach the barrel  4   a  into the receiver  402 . 
       FIG. 5A  shows the receiver  402  having the picatinny rail  410  for scope adjustment, which has grooves for receiving a sight or scope. For example, the picatinny rail  410  can be configured with the  20  MOA slope, which allows for more accurate long distance shooting. The picatinny rail  410  also allows for better usage of internal adjustment mechanisms of a scope that can be attached thereto, which is beneficial for long distance shooting. Here, the picatinny rail  410  is integrated, but it could be a separate part. The reason why it is integrated is that the muzzle loader allows for longer range shooting with accuracy, which can be facilitated with the  20  minute slope of the rail  410 . It also allows for more rigidity that enhances shooting accuracy. 
     The receiver  402  includes the upper pivot pin receiver hole  20  for receiving the pivot pin  120  and the takedown pin receiver hole  22  for receiving the takedown pin  123  as shown in other figures. 
     The receiver  402  is shown to include the bolt handle slot  412  for receiving the bolt handle  414  ( FIGS. 2B and 4A ), which bolt handle  414  can slide there along while actuating the muzzle loader for blast cap replacement. The distal end of the bolt handle slot  412  includes a ramp  416 . The other end of the bolt handle slot  412  is open as shown at  412   a.  When the bolt handle  414  is in the bolt rest  418  and pulled down into it and seated, then the rifle can fire. If the bolt handle  414  is not all the way seated into bolt rest  418 , the rifle will not fire. In some aspects, the bolt is designed to inhibit the hammer from properly actuating unless the bolt handle  414  is fully seated in the bolt rest  418 , which is described in more detail herein. 
     The extractor ramp  416  (in dashed circle) is angled from the bolt rest  418  toward the bolt handle slot  412 , which was designed to facilitate extraction of the brass from the ejection port  424  for the bolt action upper receiver. Here, the same receiver  402  can be used for the muzzle loader upper receiver and the bolt action upper receiver. It should be recognized that the receiver  402  may be modified to remove features used for the bolt action that are not used for the muzzle loader configuration. As can be seen, the bolt rest  418  and bolt handle slot  412  are at roughly 90 degrees, however, the distal or forward edge (e.g., opposite of  412   a ) has the extractor ramp  416  at an angle between the bolt rest  418  and bolt handle slot  412  instead of a 90 degree angle. This extractor ramp  416  is provided to push the bolt handle  414  in an amount and direction that was configured to initiate extraction of the brass from the chamber when in the bolt action upper receiver. As such, the muzzle loader upper receiver can omit the features for brass ejection due to not using shells. The action of the bolt still is useful for application of the charge or blast caps and withdrawal of used blast caps that are used for the muzzle loader. 
     The extractor ramp  416  also facilitates easier proximal or backward pulling of the bolt handle  414 . In some instances if heating occurs, upon manipulating the bolt handle  414  from the bolt rest  418  into the extractor ramp  416  can cause the bolt handle  414  to be pushed proximal or backwards toward the shooter to allow for a new charge (e.g., primer cap) to be installed into the charge recess of the barrel  4   a.    
     Also shown in  FIGS. 5A-5D  are the top  440 , bottom  441 , distal end  442  having the barrel opening  443 , proximal end  444  having the bolt opening  445 , the first side  446  having the first side upper surface  447   a,  first side lower surface  447   b,  and second side  448  (e.g., having a logo or other indicia) having the second side upper surface  449   a  (e.g., containing the logo or other indicia as shown) and second side lower surface  449   b.    
       FIG. 5B  shows a perspective view of some of the features of the receiver  402 . 
       FIG. 5C  shows the bottom of the receiver  402 , and shows the magazine slot  426  configured for receiving the magazine, which within includes the detent ball  428 . The magazine slot  426  opens into the hammer slot  427  (e g , hammer slot  427  narrower, proximal, and fluid with the magazine slot  426 ) configured for allowing the hammer to actuate therethrough. The detent ball  428  (in a detent recess) matches a recess  432  in the bolt  450  so that the bolt  450  stays closed and does not rattle open or rattle around during use. There is a spring in the detent recess that resiliently pushes the detent ball  428  outward so that the detent ball  428  can be pushed into the detent recess. The magazine slot can be omitted in some embodiments of the receiver  402  that are specific for a muzzle loader or are not usable with a bolt action. On the other hand, the receiver  402  can be disassembled and reassembled as either a bolt action embodiment or a muzzle loader embodiment as per the disclosure herein and in the incorporated references. 
     Near the upper takedown pin receiver hole  22 , there is a threaded hole  430 . The threaded hole  430  is adapted to receive a bolt therein so that the receiver  402  can be bolted to the lower assembly, where a fastener (e.g., threaded fastener, such as a screw, etc.) can be passed through the lower assembly into the receiver  402  and threaded into the threaded hole  430 . This can increase rigidity of the mounted receiver  402  into the lower assembly and increase accuracy of firing. Such a coupling with a fastener is optional, and if used is removed along with the takedown pin  123  and pivot pin  120 . 
       FIG. 5D  shows the other side of the receiver  402 , which shows the magazine release receiver recess  427 , which receives the magazine release button. It should be noted that the receiver  402  is contoured to fit into the lower assembly, such as the back being rounded for a tight fitting. 
       FIG. 6  shows a barrel  4   a  having a back end  602  opposite of the muzzle end  604 . The barrel  4   a  includes an annular ridge  606  a distance from the back end  602  as shown, where a cylindrical portion  608  extends from the annular ridge  606  to the back end  602 . The cylindrical portion can fit into the receiver, such as in the opening  443 . The annular ridge  606  allows the barrel nut  420  to hold the barrel  4   a  to the receiver  402 . 
       FIGS. 7A-7E  show another embodiment of a shortened bolt  702  that can be used in the ML upper receiver assembly  300 . The shortened bolt  702  is stubbed at about the handle  714 , so that it is shorter and takes up less space and is made of less material. The shortened bolt  702  can operate sufficiently with the muzzle loader configuration. The shortened bolt  702  includes a bolt tip  758  is a bolt end  780  that has a firing pin recess  782  for retaining the firing pin  704  therein. The firing pin recess  782  at the bolt end  780  shows the rear end of the bolt  702  so that the rear end of the firing pin  704  is visible. The bolt tip  758  shows the tip of the firing pin  704  within a bolt tip recess  759 . Accordingly, the shortened bolt  702  can be similar to bolt  450  with the rear end portion behind the handle omitted, which results in a simple bolt  704  for use with the muzzle loader. 
       FIG. 7A  show the bolt tip  758 , which includes the bolt tip recess  759  having an extractor  761  as part of the annular lip  763 .  FIG. 7E  shows the bolt tip  759  without the extractor  761  in the extractor slot  765 . The firing pin  704  is also shown. 
       FIG. 7B  shows the bolt end  780  that has the firing pin recess  782  with the firing pin  704  located therein. The handle  714  is adjacent to the bolt end  780 , such as adjacent to the bolt end surface  781 . 
       FIG. 7C  shows a cross-sectional view of the bolt  702  with the firing pin  407  in the firing pin recess  780  and extending to the bolt tip recess  759  of the bolt tip  758 . The extractor  761  is also shown, along with the recess for the screw that fastens it to the bolt  702 . The pin channel  707  is shown to have different dimensions to accommodate different dimensions of the pin  704 . 
       FIG. 7D  shows the bolt end  780  with the open recess  782 . The handle receiver opening  714   a  is also shown adjacent to the bolt end surface  781 . 
       FIG. 7E  shows the bolt tip  758  with the extractor slot  765  in the annular lip  763 . 
       FIGS. 8A-8E  show portions of the muzzle loader upper assembly  800  mounted to the standard lower assembly  101 A, with and without the barrel guard  801 . These figures show the arrangement of the elements as described herein. From  FIGS. 8A  to  FIG. 8F , various components are removed so that the arrangement of the outer components can be viewed relative to the inner components. For example,  FIG. 8C  shows the relationship of the hammer assembly  802  relative to the upper assembly  800  with respect to the receiver  402 .  FIG. 8D  shows a rotation from the view of  FIG. 8C .  FIG. 8E  shows a rotation from the view of  8 D. 
     In some embodiments, the present invention relates to a muzzle loader AR upper assembly as shown in the figures. The muzzle loader AR upper assembly can include a muzzle loader AR upper receiver as shown in one of the figures. The muzzle loader AR upper assembly can include a bolt of one of the figures in the AR upper receiver. In some aspects, the invention can include a muzzle loader AR upper receiver as shown in the figures. In some aspects, the invention can include a bolt for a muzzle loader AR upper receiver as shown in the figures. In some aspects, a muzzle loader AR upper assembly as shown in the figures is configured to be compatible with an AR DPMS LR-308 pattern or Armalite AR-10 pattern. In some aspects, a muzzle loader AR upper assembly is configured to be connectable with an AR lower assembly via two connection points. In some aspects, the muzzle loader AR upper assembly is configured to be connectable with an AR-10 lower assembly. In some aspects, the muzzle loader AR upper assembly is configured to be connectable with an AR-15 lower assembly. In some aspects, a muzzle loader AR upper assembly is configured to be connectable with an AR lower assembly through a pivot pin system and a takedown pin system. In some aspects, a muzzle loader AR upper assembly or upper receiver can have an upper pivot pin receiver hole that couples with a lower pivot pin receiver hole of an AR lower assembly or lower receiver via a pivot pin. In some aspects, a muzzle loader AR upper assembly or upper receiver can have an upper takedown pin receiver hole that couples with a lower take down pin receiver hole of an AR lower assembly or lower receiver via a takedown pin. In some aspects, a muzzle loader AR upper assembly or upper receiver can have: an upper pivot pin receiver hole that couples with a lower pivot pin receiver hole of an AR lower assembly or lower receiver via a pivot pin; and an upper pivot pin receiver hole that couples with a lower pivot pin receiver hole of an AR lower assembly or lower receiver via a pivot pin. 
     In some embodiments, a muzzle loader upper receiver can be configured to couple with an AR lower receiver. The muzzle loader upper receiver can include a unitary body having: a barrel end having a threaded receiver; a bolt receiving end opposite of the threaded receiver; an internal chamber extending from the bolt receiving end to the barrel end that is adapted to slidably receive a bolt therein so that the bolt can slide during actuation; a bolt handle slot extending from the bolt receiving end to a bolt rest recess, wherein the bolt handle slot opens from the internal chamber, the bolt rest recess being orthogonal with the bolt handle slot; an extractor ramp at an end of the bolt handle slot opposite of the bolt receiving end, the extractor ramp transitioning from a side of the bolt handle slot to the bolt rest recess; an ejector port opening from the internal chamber and being positioned between the bolt handle slot and barrel end; a magazine slot on the bottom of the unitary body that opens from the internal chamber, where the magazine slot narrows to a hammer slot toward the bolt receiving end (which magazine slot can be omitted in the muzzle loader configuration); an upper pivot pin receiver hole at the barrel end; and an upper takedown receiver hole at the bolt receiving end. In one aspect, the muzzle loader upper receiver can include a picatinny rail opposite of the magazine slot. In one aspect, the picatinny rail has a 20 MOA slope. This configuration can be used for a muzzle loader or for a bolt action upper receiver. 
     In some embodiments, a muzzle loader upper assembly is provided that couples to an AR lower assembly. The muzzle loader upper assembly can include the muzzle loader upper receiver of one of the embodiments and the bolt of one of the embodiments within the receiver lumen of the muzzle loader upper receiver. 
     In some embodiments, a muzzle loader AR rifle can include a standard AR lower assembly having a lower pivot pin receiver hole and a lower takedown pin receiver hole and a muzzle loader upper assembly of one of the embodiments coupled to the standard AR lower assembly by having a pivot pin in the upper and lower pivot pin receiver holes and a takedown pin in the upper and lower takedown pin receiver holes. 
     In some embodiments, a method of converting an AR rifle to a muzzle loader AR rifle can include: removing a standard AR upper assembly from a standard AR lower assembly; and mounting the muzzle loader upper assembly of one of the embodiments to the standard AR lower assembly by placing a pivot pin in the upper and lower pivot pin receiver holes and a takedown pin in the upper and lower takedown pin receiver holes. Also, a bolt action AR can be taken apart so that the muzzle loader upper receiver can be mounted to the standard AR lower receiver. 
     In some embodiments, a method of assembling a muzzle loader AR rifle can include: mounting the muzzle loader upper assembly of one of the embodiments to the standard AR lower assembly by placing a pivot pin in the upper and lower pivot pin receiver holes and a takedown pin in the upper and lower takedown pin receiver holes. 
     In some embodiments, a muzzle loader AR rifle can include: a muzzle loader AR pattern upper receiver; a muzzle loader barrel coupled to the muzzle loader AR pattern upper receiver; and an AR pattern lower receiver coupled to the muzzle loader AR upper receiver, wherein the lower receiver includes a trigger. In some aspects, a bolt can be in the muzzle loader AR pattern upper receiver. The muzzle loader AR rifle can include one or more of the following: a takedown pin hole and a pivot pin hole in an AR configuration; a ramrod coupled to the muzzle loader upper receiver; the muzzle loader barrel includes a breach plug opposite of a muzzle barrel open end; the muzzle loader barrel includes a protruding annular ridge on an external surface thereof proximal to the breach plug end with a region between the annular ridge and breach plug end surface, wherein the annular ridge on the barrel receives a barrel coupling nut that couples the muzzle loader barrel with the muzzle loader AR pattern upper receiver. In some aspects, the breach plug is screwed into the breach plug end of the muzzle loader barrel. Optionally, the breach plug has a charge side facing the muzzle barrel open end and a primer side facing away from the muzzle barrel open end. In some aspects, the breach plug includes a primer cap slot for holding a primer cap. In some aspects, the breach plug includes a nut portion adjacent to the primer cap slot. In some aspects, the breach plug includes a threading that matches a threading of the breach plug end of the muzzle loader barrel. In some aspects, the breach plug includes a conduit from the primer cap side to the charge side. In some aspects, the breach plug omits the primer cap slot, and the bolt includes a primer cap slot. In some aspects, the muzzle loader bolt is mostly cylindrical. 
     In some embodiments, a muzzle loader upper receiver can be configured to be coupled with a standard AR lower receiver. The muzzle loader upper receiver can include a unitary receiver body having a receiver lumen. The unitary receiver body can have a top; a proximal end having a bolt opening with the bolt of one of the embodiments located therein; a distal end having a barrel opening; and a bottom. The bottom can include: a hammer slot; a takedown pin receiver hole at a proximal end, the takedown pin receiver hole being orthogonal with the hammer slot; and a pivot pin receiver hole at a distal end, the pivot pin receiver hole being orthogonal with the hammer slot, the pivot pin receiver hole being parallel with the takedown pin receiver hole. A first side of the upper receiver can include a bolt handle slot extending from the bolt opening and a bolt rest slot extending from the bolt handle slot. In some options, the bottom of the upper receiver has a magazine slot open to and longitudinally aligned with the hammer slot, the hammer slot being narrower than the magazine slot. In some aspects, the first side has an ejection port between the bolt handle slot and distal end. In some aspects, the magazine slot is omitted. 
     In some embodiments, a muzzle loader upper receiver assembly can include a muzzle loader upper receiver configured to be coupled with a standard AR lower receiver. The muzzle loader upper receiver can include a unitary receiver body having a receiver lumen. The unitary receiver body can have: a top; a proximal end having a bolt opening; and a distal end having a barrel opening. The receiver can include a bottom comprising: a hammer slot; a first side having: a bolt handle slot extending from the bolt opening and exposing a portion of the receiver lumen; a bolt rest slot extending from the bolt handle slot; and the bolt of one of the embodiments slidably located in the receiver lumen. 
     In some embodiments, the muzzle loader upper receiver assembly can include a muzzle loader upper receiver configured to be coupled with a standard AR lower receiver. The muzzle loader upper receiver can include a unitary receiver body having a receiver lumen. The unitary receiver body can have: a top; a proximal end having a bolt opening; and a distal end having a barrel opening. The receiver can include a bottom with a magazine slot open to and longitudinally aligned with a hammer slot, the hammer slot being narrower than the magazine slot. The receiver can include a first side having: a bolt handle slot extending from the bolt opening and exposing a portion of the receiver lumen; a bolt rest slot extending from the bolt handle slot; and an ejection port between the bolt handle slot and distal end. The receiver can include a second side. The receiver can include the bolt of one of the embodiments slidably located in the receiver lumen. The magazine slot can be omitted in some embodiments. 
     In some embodiments, a method of forming a muzzle loader rifle can include: providing a muzzle loader AR upper receiver; and coupling the muzzle loader AR upper receiver to an AR pattern lower receiver. The method can include coupling the muzzle loader barrel to a barrel opening of the muzzle loader AR pattern upper receiver. Alternatively, the muzzle loader AR upper receiver is provided with a muzzle loader barrel coupled to a barrel opening of the muzzle loader AR pattern upper receiver. In some aspects, a bolt is in the muzzle loader AR pattern upper receiver. In some aspects, the muzzle loader AR pattern upper receiver includes a takedown pin hole and a pivot pin hole in an AR configuration, which are mounted to corresponding pin holes in the AR pattern lower receiver. 
     In some embodiments, a bolt can be configured for being included in a muzzle loader upper receiver, wherein the muzzle loader upper receiver is configured to be coupled to a AR pattern lower receiver assembly. The bolt can include a longitudinal axis and a longitudinal sequence comprising: a bolt tip; a cylindrical region; and a bolt end having a firing pin recess. In some aspects, the cylindrical region includes a cylindrical surface without any recesses. In some aspects, the cylindrical region is devoid of recesses or elevations between the front end and opener portion. In some aspects, an annular lip at the bolt tip includes an extractor in an extractor slot formed in the annular lip. In some aspects, a firing pin recess is included in the bolt and optionally a firing pin therein. 
     In some embodiments, a bolt can be configured for being included in an AR pattern muzzle loader upper receiver of an AR pattern muzzle loader upper receiver assembly, wherein the muzzle loader upper receiver assembly is configured to be coupled to a standard AR pattern lower receiver assembly. The bolt can include a unitary body having in a longitudinal axis and a longitudinal sequence that includes the following: a front end adapted to receive a charge; a cylindrical region with a uniform dimension optionally with a hammer pushing surface, where the cylindrical region can extend from the front end to an end slot or to a second end (e.g., back end or bolt tail) or to a planar surface formed into the cylinder surface in a portion of the circumference; optionally an end ramp across the end slot from the cylinder or planed surface, the end ramp extending upward; an end ridge extending from a top of the end ramp to the bolt tail (e.g., back end); if no end ramp, then the bolt may omit the end slot and the end ramp features; and a firing pin recess in the bolt end, wherein the firing pin recess optionally includes an opening from the bolt end around the end ramp and end ridge so as to be open with the end slot or it omits the opening and the bolt is cylindrical from the front end to the back end with or without the planed surface. In some aspects, the unitary body can have a first body portion of the bolt body extending from the bolt neck and terminating at a reduced dimension region (e.g., planar surface), and can have a second body portion extending from the reduced dimension region to the bolt end (e.g., a longitudinal portion with the planed surface in the cylinder). In some aspects, the cylindrical region includes a cylindrical surface, which includes a portion thereof that functions as the hammer pushing surface. 
     In some embodiments, a muzzle loader kit can include: a muzzle loader AR pattern upper receiver configured to be coupled with an AR pattern lower receiver, wherein the AR pattern lower receiver includes a trigger, the muzzle loader AR pattern upper receiver including a body with a barrel opening; and a muzzle loader barrel configured to be coupled to the barrel opening of the muzzle loader AR pattern upper receiver. In some aspects, the kit can include a muzzle loader bolt configured to slidably fit into the muzzle loader AR pattern upper receiver. In some aspects, the kit can include at least one of: a plurality of primer caps; a plurality of projectiles; charge for the muzzle loader AR rifle; or a ramrod for the muzzle loader. 
     One skilled in the art will appreciate that, for this and other processes and methods disclosed herein, the functions performed in the processes and methods may be implemented in differing order. Furthermore, the outlined steps and operations are only provided as examples, and some of the steps and operations may be optional, combined into fewer steps and operations, or expanded into additional steps and operations without detracting from the essence of the disclosed embodiments. 
     The present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods and apparatuses within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. 
     With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity. 
     It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “ a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.” 
     In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group. 
     As will be understood by one skilled in the art, for any and all purposes, such as in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as “up to,” “at least,” and the like include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. Thus, for example, a group having 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, a group having 1-5 cells refers to groups having 1, 2, 3, 4, or 5 cells, and so forth. 
     From the foregoing, it will be appreciated that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the following claims. 
     This patent application cross-references: U.S. application Ser. No. 16/818,960 filed Mar. 13, 2020; U.S. application Ser. No. 15/666,230 filed Aug. 1, 2017; and U.S. Provisional Application No. 62/373,499 filed Aug. 11, 2016, which applications are incorporated herein by specific reference in their entirety.