Well sorrtta... Powder burning rate, depth of crimp, buffer and what one, case selection, primer selection, and wad all enter into it too. To further comlicate understanding/comprehension, pressure absolutely does NOT enter into the equation to calculate recoil. The Hodgdon books/phamplets have lots of in depth explantion about these factors specifically in shotshell reloading. I think only a dude with a PhD. in physics can really "understand" it all. I just stay with below max loads, then chronograph 5-6 loads to see how well I stack up to the published data. Best, Dr. BILL
