Originally Posted by Donut SD
Well for smooth bore applications the inserts you've made I believe are fine some will still use them for standard paint. And hey, it's fun.
Right. Sizers as a detent / anti-rollout device are fine. That's a great application. Just doesn't apply when you're talking about rifling. Either the round is going to hit the rifling - in which case you don't need the sizer, or it's not going to hit the rifling - in which case you don't need the rifling.