For semi autos...you need full case resizing on your reloads. On collapsible stocks, the stock should be collapsed --- all the way in --- doing the mortar method. It is against the rules on our range, to perform the vertical mortar method. It is legal to do the mortar method, while the gun is pointed at the backstop, while banging the butt of stock against the rifle bench --- while pulling on the charging handle.
My favorite method...is to use a rubber mallet, against the charging handle; otherwise, a steel hammer can be used, along with the use of a wooden block against the charging handle.
The chamber...might need some steel chamber bore brushing.