boomer wrote on May 3^rd, 2019 at 2:06pm:

I cannot close either bolt (without considerable pressure) on brass that has been fired (in the sporter) but not yet resized.  Is there more I need to check before the question can be answered?  Do I need to check with headspace gages?  Is there something else I need to check?

What you are describing is unresized brass that has been expanded in another chamber (your sporter) which is probably 001-.002" of an inch too long or wide at the shoulder than the chamber of the rifle you are trying.

Perfectly normal. That brass will likely need to be full-length resized to make it fit.  In the match shooting world, there are fancy sizing dies that just size the neck and knock the shoulder back and in a hair to make them chamber easily. If you're going to use ammo between two different rifles, it's generally recommend to full-length resize the brass so it will feed and chamber like factory ammo. The brass will "flow" or extrude toward the case mouth which causes the brass to elongate and therefore trimming will be needed at some point.

The only down side is depending on how much the neck and shoulder of the brass are worked during these firing/sizing cycles it will harden over multiple firings and can eventually split. No good. Us crazy folk who have too much time on our hands anneal the neck and shoulder to soften the brass to let it expand and contract instead of crack. As a side effect, maintaining uniform hardness (or softness in this case) keeps the neck tension around the bullet more consistent, which enables consistent starting pressure as the powder burns, which enables more consistent velocity, which enables happiness.