SAAMI maximum chamber pressure for specific cartridges.
|7.62 x 39mm||45,000|
|300 ACC Blackout||55,000|
|300 Win Mag||54,000||64,000|
SAAMI ( Sporting Arms and Ammunition Manufacturing Institute) is an organization that defines extensive definitions for cartridges of ammunition. It includes the cartridge physical dimensions as well as maximum chamber pressure. This ensures that ammunition manufactured as a specific caliber is safe for that type of firearms with assuming a firearm in a good functioning condition.
Copper Unit of Pressure (CUP) is a measurement used in the ammunition industry to determine the chamber pressure created by a cartridge load. Originally, a precisely formed copper slug was placed in a fixture over the chamber. When the cartridge was fired, the amount of crushing measured on the slug allowed engineers to determine the pressure.
These days, modern electronic transducers provide faster, more accurate measurements of chamber pressures in pounds per square inch (PSI). CUP and PSI are measured to different scales and are NOT interchangeable.