Yep chamfering the cylinder is easy and a good idea in most cases. Sounds like you need to chamfer and go with a larger ball.
Chamfer can reduce chain fire and make loading cleaner and easier...most guns come with the chamfer, it is just so little that it is hard to see.
I just used the little hand chamfer tool that RCBS sells for brass reloading.
It worked just fine and now balls get swaged into the cylinder and don't shave the big ring. A much better seal.
If you chamfer too far/much, accuracy will be harmed.
A bigger ball will increase the size/length of the "flatspot" that is formed on the side of the ball. This will increase surface area friction..so a larger ball is also good advise.
A .457 is way more accurate and 200fps faster than a .454 out of one of my Remingtons 58's..(but it has other issues)
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