I created a thread a couple months ago about this and did not get any response, so I am going to try again. does anyone know what the psi rating is of factory AA loads, Winchester does not publish this info and says "it's proprietary". The factory load I am shooting is 20 gauge 2 3/4 shot size 8 rated at 1300fps with 7/8 oz. load. Any help on this would be greatly appreciated. Thank you, Joe