ARMY AL&T
semiautomatic operation of firearms. Some used gas ported from the barrel (a “gas port” design), while others used gas escaping from the muzzle (a “gas trap” design). Te original M1 Garand employed a fixed muzzle cap to trap muzzle gases, which then acted on a gas piston that moved in the opposite direction from the projectile.
Several other weapons tried this design; none were successful. Te problems were with the basic design concept. Once gases escape from the muzzle, they tend to cool rapidly, leaving carbon deposits behind (carbon fouling). Additionally, primers of the day used corrosive salts that required careful cleaning after use, but the complex design of the gas trap mechanism and its close toler- ances made cleaning difficult.
OVERCOMING CHALLENGES Te prototypes and early production specimens of the M1 Garand seemed to work well enough but proved to be unreliable in the field. Shortcomings included the complex procedure to clean the gas trap assembly, an unstable front sight and a weak bayonet mounting system. During field testing, a loose screw securing the muzzle cap to the barrel allowed the assembly to move out of alignment. Tis resulted in the projectile striking the gas trap assembly as the projectile exited the muzzle, taking the gas trap assembly with the projectile. Ultimately, John Garand—the rifle’s principal designer and whose name it still bears—and the Spring- field Armory in Massachusetts modified the design to employ a gas port drilled near the muzzle. Te port bled combustion gases into a closed chamber, where the gases acted on a piston at the end of an operating rod. Te cylinder and piston assembly near the muzzle was simple to remove for operator maintenance and proved to be extremely reliable.
Why did Garand initially use a gas trap mechanism, rather than a ported barrel and a closed-chamber gas piston? Although smoke- less propellants had been around for 50 years, weapon designers of the day did not fully understand or trust the technology, even with examples of successful designs in the field. Te Colt M1895 “potato digger” machine gun employed a gas port design, but its port allowed gas to move the lever as it escaped through the port and vented into the atmosphere. Te M1918 Browning Automatic
Rifle was a gas port design but was much too heavy to use as a standard individual weapon.
Distrust of the gas port was not unique to the United States. Interestingly, a 1941 German request for proposal equivalent precluded a ported barrel. Te German G41 (M) and G41 (W) both used gas trap designs similar to the early Garand design, and were unsuccessful. A follow-on to the G41 (W), the G43, used a gas piston design and was highly successful, with 400,000 produced between 1943 and 1945. However, the Americans had at least a five-year head start. Americans recognized and solved their problems with their semiautomatic infantry rifle before they entered the war.
Initial adoption of the M1 Garand did not go smoothly. Spring- field Armory produced roughly 50,000 “gas trap” rifles between 1936 and 1940. Unfavorable field experience prompted a rede- sign, from a gas trap to a gas port. Fortunately, the modification
CEREMONIAL USE
The M1 Garand is now frequently used for ceremonial purposes, including honor guards and color guards. (Photo by Petty Officer 3rd Class Elliot Schaudt)
https://asc.ar my.mil
99
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124 |
Page 125 |
Page 126 |
Page 127 |
Page 128 |
Page 129 |
Page 130 |
Page 131 |
Page 132 |
Page 133 |
Page 134 |
Page 135 |
Page 136 |
Page 137 |
Page 138 |
Page 139 |
Page 140 |
Page 141 |
Page 142 |
Page 143 |
Page 144 |
Page 145 |
Page 146 |
Page 147 |
Page 148 |
Page 149 |
Page 150 |
Page 151 |
Page 152 |
Page 153 |
Page 154 |
Page 155 |
Page 156 |
Page 157 |
Page 158 |
Page 159 |
Page 160 |
Page 161 |
Page 162 |
Page 163 |
Page 164 |
Page 165 |
Page 166 |
Page 167 |
Page 168 |
Page 169 |
Page 170 |
Page 171 |
Page 172 |
Page 173 |
Page 174 |
Page 175 |
Page 176
