45 G.A.P. hollow point ammunition is pistol cartridge that Ernest Durham (a CCI/Speer Engineer) developed at the request of Glock for use in their model 37 semi-automatic pistol. They hoped 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 ammo 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. 45 GAP hollow point factory loads are readily available from several different manufacturers in 165 grain, 185 grain, 200 grain, and 230 grain weights for those who want maximum stopping power combined with limited penetration for self defense purposes. These rounds are a solid choice for self-defense and personal protection.