.45 GAP ammo (GAP is an acronym for Glock Automatic Pistol) is a rimless, straight-walled, .451 caliber, pistol cartridge developed by CCI/Speer engineer Ernest Durham at the request of firearms manufacturer Glock for use in their model 37 semi-automatic pistol in order to create a pistol cartridge that equaled the power of the .45 A.C.P. (Automatic Colt Pistol) but which could be fired from a 9mm sized handgun.
45 GAP ammunition was the first commercially produced cartridge to be associated with Glock, the design concept of equal power from a reduced capacity case was achieved by strengthening the web of the case to prevent blowouts and carefully selecting a modern powder in order to create a cartridge with an internal chamber pressure roughly equal to that of .45 ACP +P loads.
Although the original round used a 200 grain bullet, it was later determined that the new cartridge could also be safely loaded with 230 grain bullets but, both muzzle velocity and terminal ballistics with this bullet weight are not equal to the same bullet fired from a .45 A.C.P. cartridge. On the other hand, factory loads for this cartridge are now available with 165 grain and 185 grain hollow point bullets in addition to the original 200 grain and 230 grain FMJ bullets and Magtech even produces a frangible 165 grain bullet. Consequently, the .45 G.A.P. cartridge delivers the terminal performance of a .45 caliber bullet in 9mm sized round for shooters with smaller statures who find the .45 A.C.P. too large to grasp comfortably. Check out our line-up of in-stock 45 GAP ammo for sale in the bullet categories listed below: