Forty five GAP ammunition was especially created for Glock and "GAP" essentially stands for "Glock Computerized Pistol". Engineer Ernest Durham made the 45 GAP round as a cartridge that may be as effective as forty five ACP but might have a much better case head to lessen the possibility that https://tacticalrounds.com/product-category/home-defense-shotgun-ammo/non-lethal-12-gauge-ammo/