Anyone have any experience with these? I have one that doesn't want to feed the shells very well. It WILL feed, but they catch and will mar up the tip of the bullet.

I'm thinking may be a worn magazine, but google searches say a new mag may not help.

Possibly the chamber needs polished?
It looks clean to me, but I guess there could be small burs on it.

Anybody have one or work on one in the past?