I told the new owner 8K as a reasonable level. Gave him RST and Polywad as a starting point. If the German nitro proof, in 1941, was more than 8K I could not tell him if it had passed a higher proof level than for 8K. Still, better safe than sorry and he might never shoot more than a few rounds of skeet with it anyways. I just wanted him to be safe what ever he decided to do. Nice gun but French guns all seem to be as much about style as function.