Tom,
You will probably get a number of opinions on this. If you are shooting 12ga, I would stay below 8K. Not because the guns you list couldn't take it, but why subject your babies to the possibility of premature wear. There are MANY loads below 8K. I will leave the "safe" portion of your question for those more knowledgeable than me.

My logic was that 3 tons is approx 8.9k psi. The lowest British proof I have seen is 3 tons. I then rounded down by approx 10 percent.

JMO and will be interested to hear what others think.

Ithaca1

Last edited by ithaca1; 04/11/15 09:31 AM.

Bill Johnson