45 Hole ammunition was Primarily created for Glock and "Hole" essentially stands for "Glock Computerized Pistol". Engineer Ernest Durham made the 45 Hole round as being a cartridge that could be as strong as 45 ACP but would've a stronger scenario head to reduce the probability that the case's neck https://tacticalrounds.com/product-category/home-defense-shotgun-ammo/non-lethal-12-gauge-ammo/