# Resizing Primer Cups and Anvils - We are on Cutting Edge --- JB: ###### I defer to to all machinists, engineers, and  gearheads that are exacting with  reproducible metrics concerning primer dimensions.   I'm a measly chemist.  I do have a thought that we are into somewhat uncharted waters in what we are doing, trying to recondition spent primers back to factory specs --- ###### But realistically without extreme effort we're not going to be able to do that entirely, the dimple being one of the primary issues. --- ###### I have also learned that the proper compound- with the proper degree of sensitivity -will make up in volumes for slight imperfections in cup dimensions.   In other words though it may be sacrilegious if I have to get everything exactly precise dimensionally to make a primer work with a particular compound ...that's the wrong recipe. --- PF: ###### My biggest concerns are for getting "hard cup" rifle primers mixed in with pistol primers and in how well anvils seat into cups. With my assembly method (50 hole plate), I seat anvils one or two at a time flush with the plate thickness (0.119" ). My mix of fired small primers from my pre-primer-reloading days had a wide mix from my reloads (CCI, Rem, Tula, S&B, Fiocci, Ginex) plus random primers from range pickup brass. It included both SPP and SRP. Early on, I found that mixing anvils and cups was not going to work. Some combinations would not seat, others would allow the anvil to fall out after the primers were assembled. After changing over to sorted primers, the feel when seating anvils has become much more consistent. Even so, one brand, CCI, still has an "issue" where I have an occasional anvil fall out after assembly. --- JB: ###### That is really good information Paul.  My experience has been similar to yours, the more effort I put in to keeping primer sorted by type and manufacturer the lessvmechanical issues I've seen.   Generally I found that if you have an SR anvil in an SP cup this can still work, but getting SR cups mixed with SP cups is a no-go.   This seems to be less forgiving with LRs versus LPs, most rifles will smack the primer much harder than a pistol.   Doesn't work the other way around and LRs won't seat in an LP case anyway. I seat my anvils very differently,one at a time as I case prime.  In regards to that 'feel'....if I have to push too hard especially to get it flush, then it's probably a bad mismatch