Denny,
It is more than likely the length of the brass, they can vary greatly from the same lot. If you have some calipers, measure the lengths. In PR's instructions, it mentions this and you have to close up hard on the brass the first time through the rifle. If the brass is too long it will act as a stand off and prevent it from fully locking up, and I am only talking a couple thousandths. If you have a brass trimmer or de-burr tool, this can be remedied easily.
I really don't like the idea of using the rifle as a tool to fit the brass. Before you put a primer in the brass, insert the case in the plug, take a straight edge and lay it accross the brass and the end of the barrel. If the brass is too long, it will be very obvious as your straight edge will rock back and forth. The headspace should be flush for a perfect fit, if it is sticking out only a couple thousandths, it may be too much. Instead of slamming your rifle shut to fit the brass, you can tap (NO PRIMER IN BRASS) with a brass hammer and recheck fit. or, you can find the perfect fitting piece of brass for lockup while installed in the rifle,,,remove plug,,,reinsert brass,,,measure length of brass and plug together,,,check all your brass w/plug for length using calipers.
I have had a few pieces of brass that needed a little cleaning up, but most fit pretty good from the get-go. Closing up firmly will generally make them fit well. I like them to be about .001" long to make up for the headspace built in to the design.
If the rifle locks up every time without brass in it, I'm 99% sure the brass length is the problem, and it is not locking up tight enough for the latch to adequately engage the shelf.
