In regards to brass and primer pockets in particular; just how loose is too loose? I am aware that loose fitting primers is a sign of brass that has been exposed to excessive pressure, but the term “loose” is so vague and subjective as to be nearly useless. Case in point; I have been working up loads for 375 Winchester in two different rifles, a BB94 and a Marlin 375 using cast bullets described in previous posts on this forum. I have started off with 100 pieces of brass (Winchester) and will use these exclusively for load development and will then trash the whole lot, or segregate them for plinking loads. That said, I have not been particularly careful about keeping track of how many times they (individually) have been loaded, but some are now on their 4th or 5th go-round; The mechanical force required, using an RCBS hand priming tool on some of this brass is now nearly effortless. It is not to the point that the primers are actually loose in the primer pocket, or in any danger of falling out of the brass, but the physical effort required to seat them into the case is noticeably less than with new brass……………I think. But again, this is going on “feel” and no two cases seem to be exactly the same. I am also wondering if perhaps this is just typical for Winchester brand brass, as I seem to notice similar characteristics with the 30/30 and 30-06 Winchester brass, and not so much with Remington brand.