# US 8,464,625 B2 · Barrel-mounted device for a firearm

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- Number: US 8,464,625 B2
- Document ID: US8464625B2
- Status: Granted
- Kind: B2
- Application number: 12/746,173
- Filed: 2008-10-15
- Published: 2010-11-04
- Granted: 2013-06-18
- Earliest claimed: 2007-12-03
- Assignees: DSG Technology AS
- Applicants: Andrey Albertovich Polovnev; Volodymyr Shaymukhametovich Khasiakhmetov
- Inventors: Andrey Albertovich Polovnev; Volodymyr Shaymukhametovich Khasiakhmetov
- Web page: https://patentgrep.com/patent/US8464625B2

## CPC

- F41A 21/34: Flash dampers
- F41A 21/28: Gas-expansion chambers; Barrels provided with gas-relieving ports (F41A1/06, F41A13/08 {and F41A21/36} take precedence)
- F41A 21/36: for recoil reduction (recoil reduction arrangements in general F41A25/00){; Stabilisators; Compensators, e.g. for muzzle climb prevention}
- F41A: FUNCTIONAL FEATURES OR DETAILS COMMON TO BOTH SMALLARMS AND ORDNANCE, e.g. CANNONS; MOUNTINGS FOR SMALLARMS OR ORDNANCE

## Abstract

The invention relates to rifled and smoothbore firearms and can be used in barrel-mounted devices for firing in the air and in the water. The inventive barrel-mounted device for firearms comprises a unit for joining to the barrel, a cap and a starting part with gas vents. The starting part bore is the continuation of the barrel bore, and there are N≧1 compartments formed between the casing and the starting part. Each compartment includes at least two gas vents and provides the possibility of gas exhaust from the starting part bore to the compartment through the first of the mentioned gas vents and gas exhaust from the compartment to the starting part bore through the second gas vent. The compartment length is 0.5-3.0 of the bore caliber and in the cross-section plane of the barrel-mounted device the minimal cross-section area of N≧1 compartments, designed for the gas flow between gas vents, ranges within 0.4-4.5 of the barrel bore area. The barrel-mounted device can comprise a muzzle compartment, which projects beyond the muzzle face of the starting part and has a front wall with a muzzle opening. The diameter of the muzzle opening equals to 1.05-1.2 of the barrel bore caliber. The said invention makes it possible to reduce recoil momentum, shot blast and muzzle flash while firing in the air, as well as to reduce recoil momentum and hydraulic impact in the course of underwater firing.

## Claims

### Claim 1

A barrel-mounted device in combination with a firearm comprising: a unit for joining to the barrel, a casing and a starting part with gas vents, and wherein a starting part bore is the continuation of the barrel/gun bore and there are N≧1 compartments between the casing and the starting part, wherein each compartment includes at least two gas vents and is adapted to ensure gas exhaust from the starting part bore to at least one of the compartments through the first of the mentioned gas vents and gas exhaust from the compartment to the starting part bore through the second gas vent; moreover, the compartment length is 0.5-3.0 of a bore caliber and in every cross-section plane of the barrel-mounted device intersecting at least one compartment the following condition is met:
0.4
⁢
S
K
≤
∑
i
=
1
M
⁢
⁢
S
i
≤
4.5
⁢
S
K
where:
SK —is the area of the bore;
Si —is the minimal area of the i-th compartment intended for the gas flow between gas vents;
M —is the number of compartments in the mentioned cross-section plane, 1≦M≦N.

### Claim 2 (depends on 1)

The device of claim 1, wherein the gas vents of the starting part are arranged in transversal rows containing not less than two vents each, and the total area of gas vents in every row measured from the side of the starting part bore equals to 0.3-1.5 of the barrel bore cross-section area.

### Claim 3 (depends on 1)

The device of claim 1, further comprising an additional muzzle compartment with a front wall, which projects beyond a muzzle face of the starting part and has a muzzle opening; the diameter of the muzzle opening equals to 1.05-1.2 of the barrel bore caliber, and its longitudinal axis coincides with the longitudinal axis of the starting part bore; moreover, the muzzle compartment includes at least one gas vent connecting it with the muzzle opening, and the clearance between the muzzle face of the starting part and the front wall with the muzzle opening is less than the caliber of the barrel bore; moreover in the cross-section plane of the barrel-mounted device the minimal area of the muzzle compartment cross-section intended for the gas passage from the gas vent or vents to the muzzle face of the starting part ranges within 0.4-4.5 of the barrel bore area.

### Claim 4 (depends on 1)

The device of claim 1, wherein the angle between the gas vents walls and the longitudinal axis of the starting part bore in the axial-longitudinal-section plane of the barrel-mounted device, measured from the side of the muzzle face of the starting part, ranges within 30-150 degrees, and in the cross-section plane of the barrel-mounted device the angle between the lateral walls of the gas vents ranges within 30-120 degrees.

### Claim 5 (depends on 1)

The device of claim 1, wherein each of said N≧1 compartments has at least two cross walls, and one of the at least two gas vents included into the compartment is situated close to the first of the mentioned walls and the second gas vent is situated close to the second of the mentioned walls.

### Claim 6 (depends on 5)

The device of claim 5, wherein at least one of said compartments has two longitudinal walls, which restrict the compartment in the longitudinal direction.

### Claim 7 (depends on 1)

The device of claim 1, wherein at least one compartment has a perforated partition placed between the lateral surface of the starting part and the inner lateral surface of the casing wherein in a cross-sectional plane of the barrel-mounted device the minimal area intended for the gas passage between the outside lateral surface of the perforated partition and the inner lateral surface of the cased ranges within 0.4-4.5 of the barrel bore cross-sectional area.

### Claim 8 (depends on 1)

The device of claim 1, wherein each of said N≧1 compartments has at least two perforated transversal walls.

### Claim 9 (depends on 8)

The device of claim 8, wherein said device has the option of closing perforation in the transversal walls of adjacent compartments.

### Claim 10 (depends on 1)

The device of claim 1, wherein perforation is made in the walls of adjacent compartments of the additional outer housing.

### Claim 11 (depends on 1)

The device of claim 1, wherein the starting part bore, which is the continuation of the rifled bore, is made smooth and its diameter is equal to 1.01-1.06 of the rifled bore diameter measured at rifling lands.

### Claim 12 (depends on 1)

The device of claim 1, wherein the starting part bore has rifling grooves, which are the continuation of the bore rifling grooves, the gas vents being directed along the grooves bottom wherein if said bore has more than five rifling grooves the number of vents in each row does not exceed half of the grooves and at least half of the grooves are situated between the vents.

### Claim 13 (depends on 12)

The device of claim 12, wherein the starting part is made in the muzzle of a rifled barrel and the muzzle face of the starting part fits the muzzle face of the barrel.

### Claim 14 (depends on 1)

The device of claim 1, wherein the starting part bore is made smooth and its diameter is equal to 0.99-1.03 of the smooth bore diameter.

### Claim 15 (depends on 14)

The device of claim 14, wherein the starting part bore has a muzzle taper, the minimal diameter of which is equal to 0.95-0.98 of the diameter of the starting part bore.

### Claim 16 (depends on 14)

The device of claim 14, wherein the starting part is made in the muzzle of a smooth bore and the muzzle face of the starting part fits the muzzle face of the barrel.

### Claim 17 (depends on 15)

The device of claim 15, wherein the starting part is made in the muzzle of a smooth bore and the muzzle face of the starting part fits the muzzle face of the barrel.

### Claim 18 (depends on 1)

The device of claim 1, wherein the casing is multipiece and comprises minimum two elements, and there is not less than one compartment formed between the casing and the starting part, each one including at least two gas vents.

### Claim 19 (depends on 1)

The device of claims 1, wherein the starting part is multipiece and comprises minimum two components, which are the continuation of the bore.

### Claim 20 (depends on 1)

The device of claim 1, wherein the unit for joining the barrel-mounted device comprises a grip with a conical outer surface and with an external thread and has a nut with a conical inner surface; moreover, the nut is mounted with the possibility of longitudinal movement, impact on the grip conical surface and compressing the grip.