Hello, hopefully some of the experts on this forum can help me out. About a year ago I purchased a siamese mauser action with a 45-70 barrel. The action is perfect in every respect. After some time invested to buy a beautiful birds eye maple full length stock and custom work done on the bolt, I have a glass bedded and floated big bore rifle. It feeds and ejects flawlessly. Some tell me that this rifle is in the same class as the ruger #1, and is capable of loads making over 4500 ft. lbs. of energy or more, approaching the 458 WM, putting it in dangerous game territory. Others tell me that it is only capable of marlin levergun level loads, in the 3500 ft. lbs. area. A few others, when I asked what loads are safe, responded that "Any SAAMI spec loads should be fine", which of course means black powder pressure loads (I'm fairly convinced it is stronger than this, but thats what they told me). So there it is, on asking what pressure level of 45-70 rifle this is (1, 2, or 3), I get answers in all categories, which leaves me where I started. The leade of this barrel is longer than that of my nef handi (possibly to accommodate long seating of 500 gr bullets?) The twist rate is 1-18". Leade and twist rate indicate to me a design meant for higher pressure than spec ammunition. I'd really like to shoot the Garrett and Buffalo Bore loads and equivalent reloads in this rifle, but can't bring myself to pull the trigger without more research supporting its ability to do so. Any help would be greatly appreciated.