A .50 GI next to a .45 ACP cartridge.
|Place of origin||22x20px United States|
|Designer||Vic Tibbets / Alex Zimmermann|
|Case type||Rebated, straight|
|Bullet diameter||.500 in (Script error mm)|
|Neck diameter||.526 in (Script error mm)|
|Base diameter||.526 in (Script error mm)|
|Rim diameter||.480 in (Script error mm)|
|Case length||.899 in (Script error mm)|
|Overall length||1.221 in (Script error mm)|
|185 gr (Script error g) SCHP||1,200 ft/s (Script error m/s)||591 ft·lbf (Script error J)|
|230 gr (Script error g) SCHP||1,000 ft/s (Script error m/s)||510 ft·lbf (Script error J)|
|275 gr (Script error g) JHP||875 ft/s (Script error m/s)||468 ft·lbf (Script error J)|
|300 gr (Script error g) TMJ||700 ft/s (Script error m/s)||326 ft·lbf (Script error J)|
The .50 GI pistol cartridge was developed by Vic Tibbets and Alex Zimmermann of Guncrafter Industries. The .50GI was introduced at the 2004 SHOT Show alongside the Guncrafter Industries Model No. 1, a variation of the M1911. The round has a rebated rim that is the same diameter as that of the .45 ACP. 
In 2006, Guncrafter Industries introduced its 1911 Model No. 2 which sports a full length light rail/dust cover and is chambered for the .50 GI cartridge. Both the M1 and the M2 can be fitted with Guncrafter Industries' .45 ACP conversion unit, the .45 ACP magazines hold 8 rounds.
Physically, the .50 GI round is slightly shorter than the .45 ACP but is wider. The M1 and M2 magazines can hold 7 rounds. The Glock conversion can hold 8 rounds in the standard magazine and 9 with the extended base pad.
The .50GI operates at pressures comparable to the .45 ACP, around 15,000 psi (100 MPa). Felt recoil is not unlike that of the .45 ACP. The .50GI has developed a reputation for accuracy, though this may be due to the high precision of the semi-custom and very expensive Guncrafter pistols themselves. In one test, the 300 grain (19 g) JFP (jacketed flatpoint) gave a 25-yard group of 2.24 inches, and the 300-grain JHP (jacketed hollowpoint) and 275-grain JHP gave a 25-yard group of 2.14 inches.Script error
The penetration in gelatin (but not necessarily the kinetic energy) of the .50GI is significantly different than the .45 ACP. While it is one of the few examples of the largest caliber projectile (.50) in a semiauto handgun it was purpose built to have a recoil impulse and kinetic energy substantially less than the magnum .50 caliber rounds such as the 50 Action Express (semiautomatic) or .500 S&W Magnum (revolver). Factory loaded ammunition has a kinetic energy of around 500 ft·lb.
In one evaluation the following performance difference was noted between the .45 ACP and the .50GI: "It actually pounded my steel target with so much force that it knocked the entire 100-pound plate and stand combo hard enough to make it furrow the ground it stood upon.[...]Folks, these .50 calibers really do hit that hard. [The 300 grain TMJ] caused dings in steel targets that normally fracture .40 and .45 cal rounds into so much dust." 
The cartridge is not used in law enforcement or for personal defense due to limited availability of ammunition and guns chambered for the cartridge. Currently, the only commercial handguns available in this caliber are Guncrafter Industries' own Colt 1911 handgun variants and its Glock 21 / Glock 20 conversion upper, and Magnum Research chambers their BFR revolver in this caliber on a custom basis.
- 185 gr (12 g) JHP, 1200 ft/s, 591 ft-lb
- 275 gr (18 g) JHP, 900 ft/s, 495 ft-lb
- 300 gr (19 g) JFP, 700 ft/s, 350 ft-lb
- 300 gr (19 g) JHP, 860 ft/s, 493 ft-lb
See also Edit
- .45 ACP
- .50 Action Express
- .500 S&W Magnum
- .50 caliber handguns
- List of firearms
- List of handgun cartridges
- 12 mm caliber
- Script error