jOe: I know how much thinkin' hurts, but try to follow the dots
Kent has (boomer) Bismuth loads
http://kentgamebore.com/products/bismuth-premium-shotshells.htmlKent markets Gamebore Traditional (lighter) Bismuth also
https://gamebore.com/uk/cartridge/game/12G-Gamebore-BismuthIF the box of the shells to which claycrusher is referring is marked
These cartridges are suitable for use in:
70mm case length: Guns with a chamber length of 2 3/4” or longer, nitro proofed to a service pressure of 3 1/4 tons per square inch (900 kg per square cm)
We can believe the shell maker
10,800 psi however is
not what the British consider to be 3 1/4 Tons, which I assume is the service pressure for which claycrusher's gun is proved
Trying to be of help here. Feel free to share what you've not saw and correct me. I cOuld be lying ya' knOw.