Back in 2008 when I first started reloading, I decided to pick up a 308 Winchester Lyman Case Gauge. I was loading for an LR-308, and I wanted to make sure my ammo was going to chamber properly.
The vast majority of the brass I had was once fired LC that had been salvaged from military bases, and I assumed it was most likely M-60 fired.
What I found out right away was that my resized brass would not seat flush in the Lyman Gauge when using a standard full length sizing die. I picked up an RCBS Small Base die and I could get the brass to seat, but even with the SB die I had to pretty seriously over-cam the press.
One of the first things I noticed with my reloads was I was getting flattened primers even with starting loads. I wasn't seeing flattened primers with factory ammo.
About I month ago, I decided to pick up and RCBS Precision Mic as I'm getting ready to start processing a bunch of 308 brass again. What I quickly found is that most of my previously resized brass is about .005-.008" below SAAMI specs. Eesh.
Last night I set up my Redding Type S Bushing FL die using the RCBS Mic and found that I could quite easily resize to SAMMI spec. When I put that same brass in the Lyman gauge, it is noticeably above being flush.
A little bummed that I overworked quite a bit of brass (and that I'm probably going to toss all of it after one firing), but I'm hopeful that I may have eliminated my flattened primer problem.
What do y'all think about this?