Something my brother and I did with our 3 1/4" cased black powder .45's, was to use an undersized bullet, that when PATCHED, came to .451", ie: .001" over bore diameter.

Thus, when a lubed paper patched bullet was pushed through the bore, it went easily and was marked only by the lands, just as detailed in Paul Mathews Book, when reprinting - ohhh damn- I've forgotten his name, now - a famous buffalo killer, explaining how bullets should fit the bore AFTER they are patched.

Taylor and I did this and both achieved ALMOST MOA at 100 meters - my Hoch barreled Rolling Block produced 1.3" average, while Taylor's Shiloh gave him 1.5".

The 100gr.2F in my brother's rifle and 122gr.2F in mine effectively slugged the bullets up perfectly.

The really nice aspect of this sort of patching, is that the next ctg. is easily chambered, no matter how much bullet sticks out of the case. As it, with patch, is only bore size, a proper lube on the previous shot leaves the fouling soft - chambering is easy.