Oldsnow, check your loading manuals on the trapdoor loads(45/70) and all of these loads are very low pressure and will match bp pressures. Anyone who has burst their barrel was loading silly high pressure loads . If you use the Ruger #1 loads, the pressures are way too high. But the trapdoor stuff works fine. Just stick to the lighter loads. All the barrels are mild steel from the Omega rifle to the Rem 700 centerfire. The only hardened barrels today are in machine guns. Every blowup we have heard of upon investigation, we found the owners were using magnum charges of powder.Remember in loading muzzleloaders or any rifles, start with light loads.