This 45 colt loading is Standard Pressure , which means it is safe to use in any/all 45 colt firearms in normal operating condition, yet it is a HEAVY load and is much more powerful than ordinary weenie 45 colt ammunition. This load is designed to cause disabling terminal effect, combined with the penetration required to cause fast incapacitation on human sized targets from any angle. The big flat wad cutter nose or the soft cast hollow nose crushes living tissue as it passes through it.