Didn't even think about the belt; too the .45 Sharps case (.505" SAAMI) is actually slightly smaller than the SAAMI .513" of a belted case ahead of the belt, but that part is not the problem - problem lies with the belt coming out on the solid head portion of the .45 Sharp's case. With normal loads, it might be OK, but I wouldn't do it. The barrel really should be set back 1 turn at least, I'd go 2 turns, then re-chambered - no big deal- about 2/10" shorter than now. Set back, it would be just fine.