Google
 

Thursday, September 13, 2007

M 1 Garand


Design and mechanics
The M1 rifle is a gas-operated, semi-automatic, clip-fed rifle.[28] By modern standards, the M1's feeding system is archaic, relying on clips to feed ammunition, and is the principal source of criticism of the Garand rifle. Officials in Army Ordnance circles demanded a fixed, non-protruding magazine for the new service rifle. At the time, it was believed that a detachable magazine on a general-issue service rifle would be easily lost by U.S. soldiers (a criticism made of British soldiers and the Lee-Enfield 50 years previously), would render the weapon too susceptible to clogging from dirt and debris (a belief that proved unfounded with the adoption of the M1 Carbine), and that a protruding magazine would complicate existing manual-of-arms drills. As a result, inventor John Pedersen developed an "en bloc" clip system that allowed ammunition to be inserted from above, clip included, into the fixed magazine. While this design provided the requisite flush-mount magazine, the clip system increased the rifle's weight, and prevented it from being fired without a clip, such as while reloading.
Garand's rifle was originally chambered for the .276 Pedersen cartridge,[29] charged by means of 10-round clips. Later, it was chambered for the then-standard .30-06 Springfield. With this new cartridge, the Garand had a maximum effective range of 500 yards (457 m), with the capability of inflicting a casualty with armor-piercing ammunition well beyond 880 yards (approx. 800 m). Because of the larger diameter of the .30-06 cartridge, the reworked magazine design held only eight rounds instead of ten.
Garand's original design for the M1 used a complicated gas system involving a special muzzle extension gas trap, later dropped in favor of a simpler drilled gas port. Because most of the older rifles were retrofitted, pre-1939 gas-trap M1 Garands are very rare today and are prized collector's items.[28] In both systems, expanding gases from a fired cartridge are diverted into the gas cylinder. Here, the gases met a long-stroke piston attached to the operating rod. The operating rod was therefore pushed rearward by the force of this high-pressure gas. Then, the operating rod engaged a rotating bolt inside the receiver. The bolt was attached to the receiver via two locking lugs, which rotated, unlocked, and initiated the firing cycle when the rifle was discharged. The operating rod (and subsequently the bolt) then returned to its original position.

Operation
The Garand is loaded with a full clip of 8 cartridges. Once all eight rounds are expended, the bolt will be automatically locked back and the clip ejected, readying the rifle for the insertion of a fresh clip of ammunition[29]. Compared to contemporary detachable box magazines, the M1's "en bloc" clip is light, simple, and only has to be oriented with the bullets pointing forward prior to charging the rifle (the clips have no top or bottom).
Once the clip is inserted, the bolt snaps forward on its own as soon as pressure is released from the clip, chambering a round and leaving it ready to fire.[34][35] It is advisable for the operator to ride the bolt forward with his hand (in order to prevent the bolt from closing on his thumb, resulting in the very common "Garand thumb" or "M1 thumb"), and to strike the operating rod handle with his palm to ensure the bolt is closed.[36][35]
The M1's safety is located at the front of the trigger guard. It is engaged when it is pressed rearward into the trigger guard, and disengaged when it is pushed forward and is protruding outside of the trigger guard.[36]
Contrary to widespread misconception, partially expended or full clips can be ejected from the rifle by means of the clip latch button.[36] It is also possible to load single cartridges into a partially loaded clip while the clip is still in the magazine, but this requires both hands and a bit of practice. In reality, this procedure was rarely performed in combat, as the danger of loading dirt along with the cartridges increased the chances of malfunction, not to mention the added delay in returning fire.[35][30][32] Later, special clips holding two or five rounds became available on the civilian market, as well as a single-loading device which stays in the rifle when the bolt locks back. It is also possible to modify the clip latch, disabling the clip ejection function, and thereby allowing the weapon to be charged like a traditional top-loading rifle.
In battle, the manual of arms called for the rifle to be fired until empty, and then recharged quickly. Due to the well-developed logistical system of the U.S. military at the time, this wastage of ammunition was generally not critical, though this could change in the case of units that came under intense fire or were flanked or surrounded by enemy forces.[30]
The Garand's en-bloc clip system proved particularly cumbersome when using the rifle to launch grenades, requiring removal of an often partially loaded clip of ball ammunition and replacement with a full clip of blank cartridges.

No comments: