Automatic pistol barrel and recoil compensator

A barrel and recoil compensator for a slide-type automatic pistol comprising a tubular cylindrical body member having an internal bore for forming a gun barrel and an axially movable slide chamber assembly surrounding the cylindrical body member said cylindrical body member having at one end portion for detachably securing the cylindrical body to said pistol, an opposite end portion and a shoulder portion therebetween the shoulder portion forming a first stop for the slide chamber assembly, the opposite end portion having an enlarged end cap forming a second stop for the slide chamber assembly and a reduced external diameter area adjacent the enlarged end cap, venting aperature formed through the wall of said cylindrical body member about said reduced external diameter area for venting gases from the bore of said cylindrical body member, said slide chamber assembly having at least one gas vent. The compensator is associated with a breech bolt slide of a pistol and with a recoil spring of a pistol, whereby the slide assembly while in the forward position forms a secondary pressure chamber with the reduced diameter area to equalize forces on the base of a bullet in the cylindrical body member resulting from spent gases.

FIELD OF THE INVENTION 
The present invention relates to barrels with compensators and climb 
arresters, which are particularly adapted for use with slide type 
automatic pistols and rifles. More particularly, the invention is 
concerned with the combination of a barrel and recoil compensator for 
automatic pistols and rifles of the type that automatically extracts a 
spent cartridge from a firing chamber after a shot is fired, retracts the 
bolt, ejects the cartridge and present a fresh cartridge to the chamber. 
BACKGROUND OF THE INVENTION 
It is common knowledge that hand held firearms when fired create a reaction 
force which drives the firearm upwardly. Accordingly, when such firearms 
are fired, the reaction forces create a force moment couple tending to 
twist or rotate the gun so as to cause the muzzle to climb upwardly. 
Various means and techniques have been employed by the prior art to 
overcome such upward movement. The prior art has generally provided 
compensators which are added onto the muzzle of a gun. These compensators 
add weight to the muzzle and are provided with vents to control gas 
expansion and direction. 
The principle on which the prior art compensators are based is, by adding 
weight to the barrel, the heavier barrel delays locktime of the barrel and 
this in turn reduces recoil by absorbing energy while the barrel is still 
locked to the slide. The slide then recoils with less speed and with the 
added weight the felt recoil is thereby reduced. 
Venting of the gases has been found to reduce muzzle flip. Compensators 
having an angled exhaust vector are believed to be more efficient in 
keeping the muzzle down and develop less turbulence around the exiting 
bullet than compensators that direct the gases in a 90 degree break around 
an abrupt flat-surfaced corner. 
In modern action-shooting competition handguns, compensators are of four 
common types: simple ported barrels, weighted barrel extensions, 
deflection chambers, and expansion chambers. Their function is to reduce 
muzzle flip and thereby reduce recovery time for quicker follow-up shots. 
In most of the automatic pistol compensators there are two elements of 
operation. The added weight of the device being attached to the muzzle and 
the upward venting of gases through a hole or holes in the top surface of 
the device. The combined effect is to keep the muzzle down. 
U.S. Pat. No. 2,935,000 discloses a combination torque and recoil 
compensator and barrel bushing for guns which diverts a portion of air and 
spent gases out through segmental slots. 
U.S. Pat. No. 2,313,669 relates to compensators and climb arresters. Slots 
are provided to provide a pre-release of some gases prior to action by the 
climb arrester. 
Some of the problems with the prior art devices are that the compensators 
available are intended for use with bullets of specific loads and weight. 
While these compensators may be suitable for competition shooting where 
the bullets are carefully constructed, accuracy is lost with 
non-competition guns such as utilized by the military and law enforcement 
agencies. 
The prior art post muzzle compensators also create a turbulence in the 
gases that surround the bullet in its flight path. The turbulence varies 
with the different loads of the bullets. 
SUMMARY OF THE INVENTION 
According to the present invention there is provided a barrel and recoil 
compensator for use with slide-type automatic pistols. The barrel and 
recoil compensator comprises a tubular cylindrical body member having an 
internal bore for forming a gun barrel and an axially movable slide 
chamber assembly surrounding the cylindrical body member. The cylindrical 
body member has at one end portion, means for detachably securing the 
cylindrical body means to the pistol. There is a shoulder portion between 
the end portion and the opposite end forming a first stop means for the 
chamber slide assembly. The opposite end has an enlarged end cap which is 
preferably threaded on the end so as to act as an adjustment with regard 
to barrel size. The end cap acts as a further stop means for the slide 
chamber assembly. Adjacent the end cap is a reduced external diameter area 
which together with the slide assembly forms a secondary pressure chamber 
that equalizes forces resulting from spent gases on the base of a bullet. 
Venting aperature means are formed through the walls of the cylindrical 
body member for venting spent gases from the bore. The slide chamber 
assembly is also provided with at least one gas venting means. Preferably, 
the gas venting means is in the form of a slot. 
Advantageously, the slide chamber assembly is provided with means for a 
cooperative association with the breech bolt slide and the recoil spring 
of a pistol. 
The end cap is preferably threaded onto the barrel so as to be capable of 
adapting the barrel to different types of pistols. Venting means may also 
be provided in the end cap to expedite the discharge of spent gases. 
According to another embodiment of the invention there is provided a slide 
type pistol having a receiver, a breech bolt slide reciprocally mounted on 
the receiver, and a recoil spring in combination with the barrel and 
recoil compensator of the invention. 
The objects and advantages of the present invention will become more 
apparent when reference is made to the following detailed description 
considered in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
As seen in FIGS. 1-5 of the drawings, the barrel and recoil compensator 10 
of the invention comprises a barrel 11 with a bore 25 and an axially 
movable slide chamber assembly 12 surrounding the barrel 11. 
At one end portion of the barrel 12, which is placed in a receiver of an 
automatic pistol, is a hood 17 and locking lugs 16 and 16' which lock the 
device into the receiver. The barrel 11 is also provided with barrel lugs 
21 which are used in association with holding means in the breech bolt 
slide. 
The receiver holding portion of the barrel 11 is enlarged and forms a stop 
20 for the slide chamber assembly 12. 
At the opposite end of the barrel 12 is an end cap 13 which forms a forward 
stop for the slide chamber assembly 12. The end cap 13 is advantageously 
threaded onto the end of the barrel 11 so as to provide an adjustment for 
barrel length and obtain a more secure fit in the event of variations in 
the breech bolt slide of a pistol in which it is used. The end cap 13 may 
be provided with a gas venting aperature 13 which permits escape of spent 
gases. 
At a portion 19 adjacent the end cap 13 is a reduced diameter area which 
together with the slide chamber assembly 12 in the forward position forms 
a pressure chamber. The pressure chamber equalizes the forces at the base 
of the bullet while it is still in the barrel. As a result of the pressure 
chamber, any bullet weight, velocity or bullet design still obtains 
optimum muzzle suppression without a loss in accuracy. The gas chamber 
receives about 10 to 46% of the gas pressure, typically about 25%, when a 
round is fired. 
Around the reduced diameter area 19 are gas venting aperatures 18 which 
extend through the barrel wall into the bore 25. The aperatures 18 may be 
in the form slits, slots, holes, or the like. Preferably, the aperatures 
18 have a diameter of about 0.05 to 0.15 inches and comprise one to six 
ports. 
The slide chamber assembly 12 is provided with a locking lug 22 which locks 
into a breech bolt slide of a pistol so that the slide chamber assembly 12 
moves with the breech bolt slide. An arcuate recess or recoil spring plug 
stop 23 is provided on the slide chamber assembly 12 which is operatively 
associated with a recoil spring of a pistol. The slide chamber assembly is 
provided with at least one gas venting slot 24 as shown in FIG. 1 or a 
plurality of slots 24 as shown in FIG. 6. The slide chamber assembly 12 in 
its most forward position extends completely over the reduced diameter 
portion 14 and covers aperatures 18. 
In FIG. 7 the barrel and recoil compensator of the invention is shown as 
received in an automatic pistol 30. The barrel and recoil compensator is 
shown with the slide chamber assembly 12 of FIG. 6 in the forward 
position. At the rear the hood 17 is held in the slide lug groove 31 and 
lug links 16, 16' are locked into the barrel and receiver by a pin 32. 
The recoil spring plug stop 23 is connected to the plug 32 of the recoil 
spring 33.