Greg; when a cartridge is fired, the brass case expands to fill the chamber and "STICKS" (quite solidly). When the pressure drops the brass case springs back a little.
If the case is lubed, you have effectively made a "proof load" where the case can NOT stick to the chamber while pressure is maxed out, and you load up the lugs and bolt face with *all* of the pressure the round is generating.
If my recollection is correct, the British used to slather some sort of oil/grease (molasses?) on loads to proof Enfield rifles. Or maybe they were the "blue pill" proof loaders that used 150% overpressure loads to test rifles. Can't remember. Someone did.
Maybe RC Model would know, he probably helped them design the tests back in 1890.
If the case is lubed, you have effectively made a "proof load" where the case can NOT stick to the chamber while pressure is maxed out, and you load up the lugs and bolt face with *all* of the pressure the round is generating.
If my recollection is correct, the British used to slather some sort of oil/grease (molasses?) on loads to proof Enfield rifles. Or maybe they were the "blue pill" proof loaders that used 150% overpressure loads to test rifles. Can't remember. Someone did.
Maybe RC Model would know, he probably helped them design the tests back in 1890.