The .45 GAP (Glock Auto Pistol) or .45 Glock (11.43×19mm) pistol cartridge was designed by Ernest Durham, an engineer with CCI/Speer, at the request of firearms manufacturer Glock to provide a cartridge that would equal the power of the .45 ACP, have a stronger case head to reduce the possibility of case neck blowouts, and be shorter to fit in a more compact handgun.