There is no rifling on that last inch to help with ease of getting the bullet started
the sabot the bullet sits in is made of plastic and that is the culprit. get a wire brush for ramrod and clean a little more frequently before the plastic builds up, try changing sabot ( plastic cups) some obviously melt easier than others.
When I was shooting Powerbelts, they were notorious for leaving plastic fouling in the barrel. Now I shoot Shockwaves and it is not near as bad
i used to shoot powerbelts but now i cast my own( rifling engraved at loading) bullets 320 grain when shot with 80 grains produces great patterns
I have 2 5-gal buckets of tire weights if anyone wants them. They are up in my shed in Steinhatchee. Dad and I were gonna make our own sinkers, just turned out to be more of a PIA than it was worth. Matter of fact, I need to bring the sinker mold home and sell it
