Improvements in Repeating-rifles and other Breech-loading Small-arms.
Year: 1890

page_text: Date of Application, 22nd Jan., 1890
Complete Specification Left, 22nd Oct., 1890-Accepted, 13th Dec., 1890
PROVISIONAL SPECIFICATION,
Improvements in Repeating-rifles and other Breech-loading
Small-arms.
I, KAREL KRNKA, of Vnishrady, Prague, Bohemia, in the Empire of Austria,
Ordnance Engineer, do hereby declare the nature of my said invention to be
as follows:
The objects of my invention are to arrange the mechanism of repeating rifles so
that the breech-bolt is securely held in position while firing: the position of the
breech-bolt being unaffected by the pressure of the gases; and also to effect other
improvements in repeating and other breech-loading rifles.
I form the bolt head with three radial projections or ribs at distances apart of
120 degrees. This-formation of the bolt enables me to construct the rear parts of the
breech very light and handy, even for heavy charges.
The breech cylinder is provided with a collar or flange containing three longi-
tudinal slots for the passage of the ribs, whereby the bolt, when turned by the knob
about 60°, is securely held by the three ribs in contact with the collar on the
cylinder.
A central hole is bored through the head of the bolt, to act as a guide to the pin.
The rear end of the head is screwed to the central part of the breech cylinder, and
secured in position by a small screw. The central part of the breech cylinder is
bored out to receive the striker and the spiral spring. The rear end of the striker
projects from the rear end of the breech cylinder, such projection being secured to
another cylinder, which is not permitted to revolve.
The improved construction of the bolt-head and breech-cylinder, as above described
is applicable to other breech-loading fire-arms, and especially to those of the Krnka
systems of construction.
The extreme amount of rotation of the breech is limited as usual, but in turning
the knob back the front part of the breech cylinder is caused to travel upon an
incline formed on the breech, whereby it is forced backwards about a quarter of an
inch before being drawn out. This operation loosens the cartridge previous to its
extraction.
The extractor is secured to a ring upon the breech cylinder, the hooked front end
projecting in the usual manner. so as to be ready to catch the cartridge.
The extractor has a certain amount of elasticity, and is formed with a projection,
which enters a conically formed groove in the breech-bolt, the extractor being
temporarily retained thereby. But, when pushed back, it is released from the groove,
and the hook of the extractor springs over the flange of the cartridge. The extractor
is not permitted to rotate with the breech cylinder and is only capable of moving
longitudinally, serving as a guide to the breech cylinder.
Before screwing the head of the breech bolt to the cylinder, the coiled spring is
introduced; then the striker is placed in position, with its rear end through the middle
of the breech-bolt, after which the head can be screwed in position. The rear part
of the breech bolt is then fitted to the rear end of the striker after having put
the extractor in its place, with its ring at the rear end of the middle part of the
breech bolt. The striker is then secured to the rear part of the breech bolt, so
that the two parts may move together. The rear part of the breech bolt and the
striker do not participate in the rotary movements of the middle part of the breech
bolt and its head; for which purpose the rear end of the extractor projects into a
corresponding slot of the rear part of the breech cylinder. This latter is provided
with a projection called the cock. The ring of the extractor is provided with a
projection which covers one of the slots of the ribs of the bolt head, and at the

page_text: same time keeps the extractor from turning with the bolt. The coiled spring bears
against the reduced part of the annular space and also against the collar on the
bolt. A slot along the underside of the bolt serves to limit the stroke of the breech
bolt through the sear. The rear part of the holt is retained by the sear when the
middle portion of the bolt is carried forward, and the spring is compressed. If the
trigger is drawn ready for firing, its first movement further compresses the spring,
before the end of the trigger reaches the pin of the sear, with which it is pulled down.
The rear part of the breech bolt then becomes free, and is driven forward by the
elasticity of the spiral spring, driving the striker into the cartridge. To obtain this
tension the bolt is turned to the right, after being pulled forward. The tension is
obtained although the turning of the bolt may be incomplete, as it is automatically
effected by the striker before igniting the cartridge. For this purpose helical surfaces
are provided on the collar and the head of the breech cylinder. In case of an
incomplete locking of the breech, the pressure of the striker drives the head, and the
helical surfaces cause the head to assume the correct position before ignition.
Opening the breech in turning to the left, the striker will be pushed back a small
distance and the spiral spring is slightly compressed. The tension of the spring is
completed in pulling the breech bolt forward.
In order to avoid accidental firing the rear piece of the breech boit can be turned
to the left. This keeps back the firing pin. The rear piece can be turned to the left
by its cock in case the spiral spring is compressed. The cock falls into a small recess
and at the same time if the bolt is ready for firing and the rear piece locked then the
sear springs into a recess of the rear piece, and the breech cannot be turned or opened,
as long as the breech bolt is locked.
My arrangements for repeating resemble those of my former Patents Nos. 1719788
and 1518989.
The front corner of the magazine is bevelled to enable the soldier to carry the rifle
upon his shoulder. The trigger guard is doubled, for the purpose of providing one
single plane in continuation of the magazine, and thus avoiding projections. One
elliptical opening serves for the trigger and another circular opening for the catch of
the magazine, whereby both are protected when the ride is carried upon the soldier's
shoulder. The magazine is lowered by means of two teeth and a catch.
The follower of the magazine, in my present arrangement, is split in front, for the
purpose of removal in case it needs cleaning. It is retained in the magazine by two
flaps and is pressed together upon the split portion for the purpose of removal.
In case the magazine is empty, from the whole of the cartridges having been fired,
the follower rises, so that the breech cannot be closed. This indicates that the
magazine requires refilling. But if it is desired to use single cartridges the catch of
the magazine is pressed down, as in my said former patents. The catch is continually
pressed forward by a small evolute spring. A similar evolute spring presses the
follower upwards in the magazine.
For the purpose of repeating a charged magazine is introduced from beneath; or
single cartridges may be introduced from above while the empty or partly filled
magazine being in the rifle. The magazine can finally be charged by means of a
fully charged case.
The improvements in the cramp consist in arranging it so that its sides press
together. One flank is twice as large as the other at each end. Near the back plate
each flank is split at both ends to produce a slight pressure. For keeping the
cartridges between them the flanges are provided at each end with perpendicular flaps.
For the purpose of assuring the outer cartridges, the rear plate of the cramp is
provided at each end with wedge shaped projections. These cramps can be fixed
from either side with facility, and their fanges firmly secure the cartridges. In
fitting the cramp upon its place to charge the magazine in the rifle, the shorter flange
will appear in each case on the top to the right, so that, with the thumb of the right
hand, the soldier can press down cartridges into the magazine. When the half of the
last cartridge leaves the cramp, the elastic flanks of the cramp close up together and
the cramp slides off the last cartridge.

page_text: In this manner my new cramps extract themselves automatically, without any
particular implement being required, thus effecting also a saving of time.
Dated 2nd Tonna 1800
GEO.
DOWNING,
8, Quality Court, London, W.C., Agent for Applicant.

page_text: Figure 28 shows the trigger guard as seen from below.
Figures 29 and 30 are views of the trigger bar.
Figures 31 and 32 are views of the trigger spring.
Figures 33 and 34 are views of the sear.
Figures 35, 36 and 37 are views of the magazine catch.
Figure 38 is a plan of the magazine, filled.
Figure 39 is a longitudinal section of the same.
Figure 40 is a transverse section of the empty magazine according to the
line X*X*.
Figures 41 and 42 are views of the cartridge follower.
Figure 43 is a side view of the filled cartridge cramp.
Figure 44 is a front end view of the empty cartridge cramp.
Figure 45 is a longitudinal section of the same.
Figure 46 is a side view of the same.
The breech holt head A is so formed that on its front end are situated three breech
ribs a of equal size, extending exactly radially from the body of the breech bolt head,
and at equal distances.
During firing, the flattened shoulders of these three breech ribs rest against the
collar like steps f¹ in the shoe F (Figure 9) in which is formed the cylindrical
chamber which is of such a diameter that the breech ribs can rotate in the same,
around the axis of the bolt.
The collar or shoulder f¹ thus formed is recessed at three places; serving to receive
the breech bolt and coinciding with three grooves f' corresponding to the three before
mentioned breech ribs a.
These three grooves f' run through the whole length of the shoe and into the
cylindrical chamber f.
These grooves are best shown in Figures 8 and 9 and are designed to allow of the
forward and backward movement of the breech bolt, and the three breech ribs a
respectively.
As soon as the three breech ribs a (Figure 19) have been pushed into the chamber f,
they are turned sixty degrees around the axis of the breech bolt by means of the
handle b whereby the perfect symetrical closure of the breech is effected because the
resting points of this locking mechanism are arranged on the periphery of the breech
bolt at equal distances, and because the 3 bearing points or surfaces distribute well
the pressure, and at the same time permit a small rotation of the breech bolt to
complete the locking. The breech bolt head A is hollowed longitudinally for the
reception of the firing pin and its sear, and is screw-threaded to enable the breech bolt
head to be screwed to the centre piece B. The connection of these two parts (see
Figure 16) is effected by means of the set screw b¹, in such a manner that both parts
commence and complete their movements simultaneously. The breech centre piece B
is also hollowed longitudinally to receive the firing spring d, and the longitudinal part
of the firing pin 1. From the upper surface of the centre piece B protrudes the
handle by means of which the breech is closed or opened. To close the breech, the
handle b, is pushed forward, and then rotated towards the right.
In order to open the breech the handle is turned towards the left and then pulled
back.
It is intended that this symmetrical breech bolt head may be used for a straight
pull breech bolt, in which case the rotation of the breech ribs is effected automatically
at the end of the forward movement of the handle, without it being necessary to first
turn the handle. It may be used in this manner for instance in a straight-pull breech
bolt system.
From the breech centre piece B, projects further a projection 6², which serves first
as a boss for the screw b¹ and secondly in combination with a socket-handle b, to limit
the rotation of the breech bolt to the proper angle.
When the breech is opened the projection 2 comes against the left wall of the shoe
and thus prevents further rotation in the opposite direction.
Thirdly the projection is also intended to loosen the jammed cartridge-case after

page_text: firing, when the breech is opened, so that the empty case cannot offer any resistance
to the backward movement of the breech bolt.
During the rotation of the breech bolt to the left (see Figure 2) this projection 6³
comes against the oblique face f³, and slides along the same, so that, without direct
manipulation by the hand in this direction, the breech bolt is pushed back five
millimetres before the rifleman commences the direct pulling back of the breech bolt.
In order to prevent the hooked head of the cartridge extractor E (Figure 14),
which is attached by means of its ring e to the rear of the breech centre-piece B,
from sliding off the cartridge rim, in consequence of the longitudinal elasticity of
the extractor, the following arrangement has been designed. The breech bolt head
cylinder A is surrounded directly behind the breech bolt, by the groove a', which is
under-cut so that its upper edge hangs over (see Figure 16).
The cartridge extractor (see Figure 13) is provided with a projection el corre-
sponding to this groove a¹ (see Figure 13). This projection is a little smaller than
the groove, so that the cartridge extractor can move a little forward or backward as
required. When the cartridge is pushed into the barrel the cartridge extractor is
thrown back a little distance at the closure of the breech, in consequence of its
striking the cartridge rim, and as in this case its elasticity is not confined, the hook
of the cartridge extractor is allowed to slide over the cartridge rim at the closing of
the breech.
A cartridge from the magazine is pushed forward by the cartridge extractor as soon
as the former leaves the magazine, and also as soon as a cartridge is thrown into the
loading recess of the shoe for single firing. When the breech is opened the breech-
bolt recedes by itself at first, whereby the projection e¹ is brought under the
overhanging side wall of the groove a¹ thus taking away the elasticity of the
cartridge extractor. The more resistance the cartridge case offers, the less becomes
the elasticity of the cartridge extractor, and the stronger the grip of the latter on
the rim.
By the continued and complete withdrawal of the breech bolt the case is extracted
from the shoe in the following manner.
The space between the hook of the cartridge extractor and the left wall of the shoe
is much smaller than the rear diameter of the cartridge case. As the cartridge
extractor at the withdrawal of the breech bolt protrudes forward, the cartridge case
cannot be withdrawn when its bottom is perpendicular to the longitudinal axis of the
shoe, but its front end endeavours to find room towards the right, and as soon as the
breech bolt has been sufficiently withdrawn to satisfy this tendency of the case,
the latter is extracted completely from the shoe. The cartridge extractor of course
does not join the rotary movement of the breech bolt as it is prevented from doing so
by a corresponding groove in the shoe, which only allows its longitudinal forward and
backward movement.
The cartridge extractor therefore serves as a guiding bar for the breech bolt.
The firing spring d and the rear end of the firing pin D are introduced into the
breech bolt centre-piece before the breech bolt head A is screwed on to the latter.
Then the rear end of the firing pin protrudes a considerable distance backward out of
the breech-bolt centre-piece B. Un to this protruding end is pushed the breech bolt
rear piece C, after the cartridge extractor Elias been pushed over the centre
piece B by means of the ring e. By means of the screw nut c the firing pin D is
connected to the rear piece ( so that these two pieces make all movements together.
To further secure this connection the rear spindle of the firing pin D (see
Figures 10, 11 and 16) has a small projection d' reaching into a groove of the breech
bolt rear piece, thus ensuring the joint action of these two parts.
The breech-bolt rear piece C and the firing pin D do not join in the rotary
movement of the breech bolt centre piece B and the breech head A.
To absolutely prevent such rotation at the opening and closing of the breech bolt
the rear arme of the cartridge extractor (see Figure 17) reaches into the guiding
groove c' in the breech-bolt rear-piece C, and as the cartridge extractor can only
move forward and backward, any rotary movement of the breech rear-piece is

page_text: prevented by the extractor. In the moment of the complete cocking, the pro-
jection has already entered a little distance into a slot in the shoe.
Before cocking, the end of the arm e² is at the rear end of the groove c'. As
before described the middle part of the cartridge extractor E is formed as a ring e to
surround the breech centre-piece B, without interfering with the rotary movement of
the latter.
The protruding parts of the cartridge extractor are placed partly in the right hand
breech rib groove 7 of the shoe and partly into a separate groove f* (see Figure 9).
Besides the cartridge extractor rod E the cartridge extractor ring e is supplied with
a guiding stud e³ (see Figure 13) which is however only of secondary importance and
serves chiefly as a stopper to the left hand breech rib groove in the shoe, which
otherwise would remain uncovered. Of course this stud also assists to prevent a
forward rotation of the cartridge extractor.
The rear end of the firing spring d (see Figure 10) bears against the rear end of the
breech bolt centre piece B, and thus always pushes the firing pin completely forward,
being prevented from further expansion by the firing pin cover d². On the lower
periphery of the breech bolt head (see Figure 20) runs from the circular groove a¹
the sear groove a² and in continuation of it, the groove 63 of the breech-bolt centre-
piece, which passes through the cartridge extractor ring e, and finishes at the edge of
the rear cylinder of the breech-bolt centre-piece B.
These grooves, thus connected, form a longitudinal groove through the two
forward breech bolt parts and the ring e. This common groove serves for the
reception of the sear 'h which also limits the back ward movement of the whole breech
bolt (see Figure 3).
When then, the breech-bolt is pushed forward, the rear piece C is kept back by the
sear, thus compressing the firing spring. This is effected (see Figure 16) because the
firing pin D is kept back, while the breech-bolt centre-picce B, during the continued
forward and rotary movement takes the rear part of the firing spring forward, the
front part of the latter being kept in position by the breech-bolt collar d².
When then the trigger bar H (Figure 3) is pressed for the firing of the rifle, at first,
when the forefinger is bent, the trigger bar H is moved alone, while the spring ³ is
somewhat pressed, but when the bending of the finger is continued the fore part of the
trigger bar H presses down the sear / by engaging with the sear pin 1. The breech-
bolt rear-piece C is thus freed from the sear h, and is thrown forward to the extent
shown in Figure 10, by means of the rapid expansion of the firing spring d.
To cock the breech-bolt in this manner, it must be rotated to the right and locked
after having been pushed forward, or the recoil of the firing spring will draw the bolt
back again.
When this roiation of the handle b has been effected, even in part, the compression
of the spring is determined.
If the handle should not be completely turned the final locking of the breech-bolt
is effected as follows: by means of the firing pin, before the latter fires the cartridge.
The firing pin collar d² has a projection forming a segment of a screw thread (see
Figure 16) and in the breech-bolt head A there is a screw-like recess corresponding to
the before-mentioned projection. When the breech is not completely closed the said
recess of the breech-bolt head A is not exactly opposite to the segmental screw
projection d as in Figure 16.
When the firing pin is in this position, and is thrown forward by the spring, it
places the breech-bolt head A in a right position, by means of the reaction of the
said segmental screw projection and recess.
During the opening of the breech when the bolt is rotated towards the left, the
firing pin D is pushed back by this device, and the firing spring d is thereby
somewhat compressed (see Figure 3). The complete compression of the firing spring d
is effected when the breech-bolt is pushed forward and locked as described.
To prevent accidental firing of the loaded, cocked, and closed rifle (particularly
during any movement) the breech-bolt rear-piece C can be rotated to the left behind
the shoe, thus arresting the firing pin in all cases. For this purpose the breach-

page_text: bolt rear-piece C is provided with a projection c³, by means of which the former cau
be turned to the left (see Figure 17) when the breech-bolt is cocked; and also the
groove c runs into the transverse groove c² (see Figures 17 and 20) to admit of the
piece (turning on the fixed extractor.
On the rear end of the shoe (see Figure 5) is further the oblique face f³ over which
the projection e³ can slide to enter the recess f. In this case firing is prevented,
and at the same time the breech-bolt is completely locked, which is effected in the
following manner :-
On the rear cylinder of the breech-bolt centre-piece B is the separate longitudinal
groove 4, which, when the breech has been completely closed, is situated directly
opposite the sear (see Figure 10). When however the breech-holt is cocked, and
the firing pin arrested, as in Figure 22, the sear engages into this groove b₁, and
thus prevents the rotation of the breech-holt and the opening of the breech, as long
as the firing pin is arrested.
When, as shown in Figure 24, the projection c³ is turned back into its normal
position, as in Figure 12, the breech-bolt rear-piece C Figure 22 presses at the same
time the sear down out of this groove ; that is to say by the pressure which the
breech rear-piece C can now effect against the oblique face 2 of the sear h.
When the breech is co pletely closed, and the breech-bolt at rest, Figure 10, the
the sear engages into the groove ct of the breech-bolt rear-piece C, in order to reduce
the compression of the firing spring d (see Figure 10).
The handle b, and its socket are turned to engage with the shoulder f² of the shoe,
in the same manner as the three breech ribs before described engage in their locking
(see Figures 1 and 2).
The breech-bolt is thus locked twice, this second locking is however not real
because there is a very small space between the socket of the handle, and the shoulder f³
of the shoe.
When the rifle has been used for a considerable time this intermediate space will be
become less as the breech-bolt heal A is found to be upset in time, in consequence
of the high pressure of the gas. If this small intermediate space has become so much
reduced that the rotation towards the left of the handle produces friction on the
shoulder of the shoe, it will be apparent to the rifleman that the breech-bolt head A
must be exchanged for a new one, nevertheless the handle is also available for safety
locking, that is to say in case the breech-bolt head should be subjected to so heavy
a strain, that the breech ribs a might break off by the gas pressure.
It is hardly necessary to take into consideration the possibility of this taking place,
but, if it were to happen, the handle will stop the recoil of the breech-bolt.
The lower front corner of the magazine is reduced, as in Figure 1, to enable the
bearer to shoulder the rifle conveniently.
In order to have the lower surface of the magazine on one level with the lower
surface of the trigger guard G, the latter has been extended accordingly. The
elliptical recess is designed for the trigger bar, and the circular recess g' for the
magazine catch I, to allow of the latter being pressed back for lowering the magazine
to enable the rifle to be used for single loading.
The duplicate trigger guard G, therefore protects the magazine catch from being
pressed back accidentally, the uniformity of these two lower surfaces of the trigger
guard and magazine, further allows of the rifle being also shouldered at this place.
To disengage the magazine the catch is pressed back by means of a thin packing
piece a greater distance than would be possible with the bare fingers; the magazine
is then thrown out by the pressure of the two springs g². The rifle may also be used
for single loading by the two springs g² being bent towards each other, and thus
serving as a rest for the cartridges fed singly into the recess of the shoo.
The front half of the cartridge follower k, Figure 42, is slit, to allow of being
removed from the magazine for cleaning, when the follower is kept back by the two
lugs ³ Fig. 38, as its two elastic arms can be pressed together for this purpose.
When the magazine has been emptied by repeated firing, the rear end of the
cartridge follower k, Fig. 39, rises so high that the breech-bolt cannot be pushed

page_text: forward. this serves as a signal to the rifleman that he must refill the magazine, or, for
single firing, he has to press the magazine catch I to allow of the magazine being
lowered. The catch I is always pressed forward by the spring i. To ensure the base
of the magazine spring k being perpendicular to the longitudinal axis of the latter, a
supporting wedge slightly hollowed at one side is introduced on the bottom of the
magazine.
For repeat-firing the filled magazine may be introduced from below, or, if the
empty or partially empty, magazine is already attached to the rifle, single cartridges
may be fed from above. The magazine can aslo be filled by packets by means of any
suitable cartridge cramp.
My improved cartridge cramp is shown in Figures 43, 44, 45 and 46.
The two sides, or cheeks are elastic at their upper and rear ends.
On either end of the cartridge cramp one of the sides overlap the other by its
double width near the rear wall, the sides are perforated below and above to
increase their elasticity.
To prevent the cartridge from falling off the cartridge cramp, both sides of the
latter are somewhat bent inwards, at a right angle at each end.
To allow of the cartridges being pressed easily downward from the cartridge cramp,
the cartridge rims are not in a straight line groove, but in a bent groove, so that the
cartridge rims are not placed beside each other, but above each other; while at the
same time the front parts of the cases of all five cartridges touch one another. The
back of the cramp is indented with tongues on both ends, according to the bend of
the groove (see Fig. 45) to prevent the accidental slipping of the most rearward
cartridges.
The cartridge cramp can therefore be emptied from either side, and the sides l, in
consequence of their radial position, effectively prevent the shaking of the cartridges,
and have the other following advantages.
As shown in Fig. 3 the filled cartridge-cramp is placed in the corresponding recess
of the shoe, whether this is done with one end, or the other, the narrow end of one
of the two sides l is always situated upwards to the right of the rifle, the cartridges
are then pressed downward with thumb of the right hand, one by one, the cartridge
cramp remaining stationary as the lower end of the two sides 11 rest against the
elastic magazine lugs k².
Directly one half of the last cartridge has left the cramp L the latter is thrown
upwards on account of the elasticity of its two sides 11, by means of the rectangular
bend of the edges of the sides, and slips suddenly off the surface of the
cartridge in this manner the new cartridge cramps are extracted automatically,
without any special device on the rifles, and save the rifleman the trouble of extracting
them by hand.
Having now particularly described and ascertained the nature of my inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1st. A symmetrically formed breech-bolt head A, for breech-bolts for fire-arms,
with three radially extending breech ribs a, situated at equal distances apart, and in
connection therewith a cylindrical chamber between the loading space of the barrel
and the breech seating of the breech-bolt in the shoe F, as described.
2nd. A circular groove a¹ on the front end of the breech-bolt, behind the breech-
bolt, closing faces around the whole, or part of the periphery of the breech-bolt, and
undercut in order to limit, or take away the elasticity of a cartridge extractor E,
bridging and engaging in such groove, by means of a stud or projection e' on the
cartridge extractor.
3rd. A sear h engaging in a recess 6 (which keeps the breech-bolt locked, when
the firing pin is intentionally arrested, by the turning of the rear block c) and
provided with an inclined face h² by which the sear can be pressed downward, a
certain distance by the firing pin and attachment C, either directly or indirectly to
release the locking of the bolt, when the bolt and firing pin is cocked ready for firing.

page_text: 4th. The construction of a double trigger guard G embracing both the trigger and
the magazine catch for the purpose described.
5th. A cartridge cramp L in which the cartridges are situated radially, and
having a back partially indented inwards and elastic sides to throw out the cartridge
cramp automatically from the shoe.
Dated this 22nd day of Databox 1800
FELL & WILDING,
1, Queen Victoria Street, Agents for the Applicant.