45 Hole ammunition was Primarily designed for Glock and "Hole" basically stands for "Glock Automatic Pistol". Engineer Ernest Durham intended the 45 Hole round to be a cartridge that might be as powerful as 45 ACP but would've a more powerful circumstance head to reduce the probability that the case's https://tacticalrounds.com/product-category/home-defense-shotgun-ammo/non-lethal-12-gauge-ammo/