US20020121741A1

US20020121741A1 - Durable system for controlling the disposition of expended munitions fired at a target positioned close to the shooter

Info

Publication number: US20020121741A1
Application number: US09/801,175
Authority: US
Inventors: Philip Malone; Charles Weiss; Brad Huntsman; Brent Huntsman
Original assignee: Individual
Current assignee: US Department of Army
Priority date: 2001-03-05
Filing date: 2001-03-05
Publication date: 2002-09-05
Anticipated expiration: 2021-03-05
Also published as: US6446974B1

Abstract

In a shooting range for training personnel in the use of firearms, a bullet trap that prevents rebounding bullets or flying debris from injuring shooters, has a central section of stacked cylindrical logs, or logs having a trapezoidal cross section, supported by stacked rectangular supporting blocks on each side. The stacked cylindrical logs have conical end sections at the end facing the shooter. These conical end sections direct incoming bullets to passageways between the cylindrical logs. Bullets passing through these passageways then strike a backstop panel. In a preferred embodiment, both the cylindrical logs and the backstop panel are made of shock-absorbing foamed fiber-reinforced concrete.

Description

GOVERNMENT INTEREST STATEMENT

[0001] The invention described herein may be manufactured, licensed and used by or for governmental purposes without the payment of any royalties thereon.

I. BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a bullet trap that includes a screen that protects persons at a firing range from being struck by rebounding bullets or flying debris generated by the impact of bullets.

2. Prior Art

Bullet screens and traps used on firing ranges are known to the art. U.S. Pat. No. 4,821,620 discloses an anti-spatter screen made of rubber-like material adapted to self-closing is secured to the front face of a deflector plate. U.S. Pat. No. 5,564,712 discloses a bullet trap for indoor shooting with small arms using a vertically-suspended rubber curtain and a vertically-suspended steel impact plate. U.S. Pat. No. 5,486,008 describes a bullet trap having a passageway between upper and lower boundary walls converging on a deceleration chamber. U.S. Pat. No. 5,718,434 discloses a bullet trap for pistol and rifle ranges having one or more deflecting plates having curved sections which direct bullets toward a back wall and a final impact plate. U.S. Pat. No. 5,988,647 describes a projectile trap having three groups of suspended polyurethane sheets in which these sheets have increasing hardness as a bullet traverses them.

The present invention relates to a bullet trap which is durable and nonflammable, and which allows a shooter to practice safely at close range. The bullet screen of the bullet trap in accordance with this invention is more durable than conventional bullet screens using wood and elastomers, which deteriorate quickly after repeated shots, and which may be set on fire when certain munitions are fired. The bullet trap of this invention has conical heads that guide bullets into passageways that traverse the bullet screen.

II. SUMMARY OF THE INVENTION

The bullet trap of this invention serves to confine rebounding bullets and flying debris generated by bullet impacts, preventing them from traveling to the area where personnel are stationed during shooting exercises. The bullet trap is placed behind a target and in front of a bullet-absorbing backstop panel.

The bullet trap of this invention consists of a bullet screen supported by blocks on each side, as described more fully below. The bullet screen consists of cylindrical logs having conical heads at one end, stacked such that their circular cross sections are on square or equilateral triangular centers and their conical heads are pointing towards incoming bullets. The square or triangular stacking of the cylindrical logs provides passageways along the sides of the logs into which bullets are directed. Alternatively, the logs may be trapezoidal in cross section and be stacked in such manner as to provide passageways for the passage of bullets along the sides of each log. The ends of the logs, in this alternative configuration, are formed to have a chisel-like shape and face incoming bullets.

The stacked logs are held in place by stacks of rectangular blocks (herein referred to as supporting blocks) on both sides of the logs. The conical heads, or chisel-shaped ends as the case may be, guide bullets approaching the bullet screen towards the passageways that traverse the bullet screen as a result of the square or triangular stacking of the cylindrical logs. In-coming bullets strike the conical heads of the logs at a low angle and ricochet into the passageways between the logs. Bullets may make several more low-angle ricocheting impacts on the sides of the conical heads of the logs before traversing the screen and impacting on the bullet-absorbing backstop panel. When logs having trapezoidal cross sections are used, bullets make corresponding contact with the chisel-shaped heads having tapered faceted faces and have the same effect as the conical heads. The narrowness of the passageways between the logs and the limited kinetic energy or momentum of the rebounding debris virtually eliminate the possibility of any bullet or any debris returning to the shooters' station.

An advantage of the bullet trap of this invention, in a preferred embodiment, is that the bullet screen logs are made of shock-absorbing, foamed, fiber-reinforced concrete. This concrete may contain a slight excess of calcium hydroxide which, when exposed to rain and moisture in the field, produces a slightly alkaline leachate that reduces the amount of heavy-metal contamination leaving the range, e.g., lead contamination that may result from the firing of lead bullets. Furthermore, in this preferred embodiment, the trap does not require any preservative or coating to prevent rotting or insect attack, and therefore has low maintenance requirements. The concrete bullet trap of this preferred embodiment may be used with tracer, incendiary, or deflagrating ammunition without fire hazard. Other materials such as wood or elastomers may be used in building bullet traps where fire hazards are low and durability is of secondary importance.

III. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing the placement of the bullet trap with respect to the shooter, target, and backstop panel. FIG. 2 shows a view of the bullet screen including supporting blocks.facing the shooter. FIG. 3 shows a side view illustrating the stacking of cylindrical logs used in building the bullet screen. [0011]

IV. DETAILED DESCRIPTION OF THE INVENTION

With reference to FIG. 1, a [0012] shooter 1 shoots a bullet which passes along a bullet trajectory 2 and strikes and penetrates a target 3. The bullet continues along its trajectory and strikes a bullet screen 4. The bullet may become embedded in the material of the bullet screen or, more likely, penetrate it by passing through passageways created by the shape of the stacked bullet screen logs. After the bullet penetrates the screen 4, it travels on and strikes a backstop panel 5. At this point, the bullet and any flying debris that may have been dislodged from the backstop panel 5 have insufficient momentum to rebound and re-penetrate the screen while traveling in the opposite direction towards the shooters. The bullet and any debris will fall to the bottom of the space between the screen 4 and the backstop panel 5.
FIG. 2 shows a front view of the [0013] bullet screen 4, which is made of cylindrical logs 6 stacked on top of each other.such that their circular cross-sections are on square or equilateral triangular centers and their conical heads 8 are pointing towards incoming bullets. The square or triangular stacking of the cylindrical logs 6 provides passageways 9 along the logs. The cylindrical logs 6 are held together by large, preferably rectangular, supporting blocks 7 on both sides 10 of the stack of cylindrical logs 6. The supporting blocks 7 are piled to a height sufficient to support the height of the stacked screen logs.
Typical dimensions of the cylindrical logs are: diameter, 6″ (15 cm); length of cylindrical portion, 3 ft (90 cm); length of conical portion, 1 ft (30 cm). It is to be understood that these dimensions are typical but not limiting. Shock absorbent material used in making the logs for the [0014] screen 4, preferably, is foamed, fiber-reinforced shock-absorbent concrete (SACON) weighing, typically, 90 lbs. per cubic foot (1.4 grams per cubic centimeter). The diameter of cylindrical logs, typically, is about 6″ (15 cm). Each log weighs about 60 lbs. Bullet screens of this type can be used with weapons up to 0.50 caliber (12.7 mm). As noted, they can be used with tracer, incendiary, and deflagrating bullets without risk of igniting the screen.
The supporting blocks [0015] 7 holding the stacked bullet screen logs 6 in place may be wooden boxes filled with sand, or SACON which may contain a slight excess of calcium hydroxide, as described above which, when exposed to rain and moisture in the field, produces a slightly alkaline leachate that reduces the amount of heavy-metal contamination leaving the range, e.g., lead, that may result from the firing of lead bullets.
The dimensions of an installed bullet trap, typically, are as follows: width of the bullet screen, 8 ft (2.4 m); height of the bullet screen, 8 ft (2.4 m); and depth of 4 ft (1.20 m). including the conical heads. The width of the supporting [0016] blocks 7 for retaining the bullet screen is 2 ft (60 cm) on each side of the bullet screen; the height of the blocks is 2 ft (60 cm); the length of the blocks 7 is 3 ft (90 cm). A firing range 8 ft. high would have supporting blocks stacked four blocks high. It is to be understood that these dimensions are typical but not limiting.
It will be understood that the foregoing description of preferred embodiments of the present invention is for purposes of illustration only, and that the various structural and operational features herein disclosed are susceptible to a number of modifications and changes, none of which entail any departure from the spirit and scope of the present invention as defined in the following claims. [0017]

Claims

What we claim is:

1. A bullet trap for confining bullets and flying debris resulting from bullet impact comprising:

(a) a bullet screen composed of a plurality of cylindrical logs, each having a conical head at one end thereof, said logs being stacked such that the conical heads face incoming bullets;

(b) said stacked cylindrical logs forming passageways between them to provide passage for bullets through the bullet screen; and

(c) supporting blocks for retaining the stacked cylindrical logs on two opposing sides thereof.

2. The bullet trap of claim 1 wherein the logs are made of shock-absorbing material.

3. The bullet trap of claim 1 wherein the supporting blocks are made of shock-absorbing material.

4. The bullet trap of claim 2 wherein the shock-absorbing material is fiber-reinforced foamed concrete.

5. The bullet trap of claim 4 wherein the fiber-reinforced foamed concrete further comprises calcium hydroxide.

6. The bullet trap of claim 3 wherein the shock-absorbing material is fiber-reinforced foamed concrete.

7. The bullet trap of claim 1 wherein the supporting blocks are stacked rectangular blocks.

8. The bullet trap of claim 7 wherein the rectangular supporting blocks are wooden boxes filled with sand.

9. The bullet trap of claim 1 further comprising a bullet-absorbing backstop panel disposed behind the bullet screen.

10. A bullet trap for confining bullets and flying debris resulting from bullet impact comprising:

(a) a bullet screen composed of a plurality of logs having trapezoidal cross sections, each log having a tapering faceted head at one end thereof, said logs being stacked such that the tapering heads face incoming bullets;

(b) said stacked logs forming passageways between them to provide passage for bullets through the screen; and (supporting blocks for retaining the stacked cylindrical logs on two opposing sides thereof.11. The bullet trap of claim 10 wherein the logs are made of shock-absorbing material.12. The bullet trap of claim 10 wherein the supporting blocks are stacked rectangular blocks.