bote Posted March 24, 2015 Share Posted March 24, 2015 I get a variation of up to .005" in my 30-06 cases as measured in a Hornady LnL comparator. Talked to Dillon on the phone today and the tech said this was normal. I realize brass can spring but this is more than I've seen in a single stage. Link to comment Share on other sites More sharing options...
Iowa Fox Posted March 24, 2015 Share Posted March 24, 2015 I'd anneal a few and then try. See what you get .005 might be all a 550 can do. This is exactly why a lot of guys have a 450 in the herd. Link to comment Share on other sites More sharing options...
jeffabuck Posted April 10, 2015 Share Posted April 10, 2015 there is an awesome article out there about the science behind annealing brass. unfortunately i am too new to post the link to the web site here.. so: bisonballistics.com/articles/the-science-of-cartridge-brass-annealing is the url. many youtube videos out there as well, both diy and buy my machine now. most are good ideas and pretty easy to fabricate. The one I liked best was annealeez. Link to comment Share on other sites More sharing options...
benos Posted April 10, 2015 Share Posted April 10, 2015 I get a variation of up to .005" in my 30-06 cases as measured in a Hornady LnL comparator. Talked to Dillon on the phone today and the tech said this was normal. I realize brass can spring but this is more than I've seen in a single stage. Where does the .005" variation occur? Link to comment Share on other sites More sharing options...
blairmckenzie1 Posted April 10, 2015 Share Posted April 10, 2015 same head stamp brass? Link to comment Share on other sites More sharing options...
808win Posted April 20, 2015 Share Posted April 20, 2015 (edited) jeffabuck, that was a good article on cartridge case annealing. Thanks. bote, I struggled with (shoulder datum to case head dimension) variations just trying to full length size .223 Rem cases using a single stage O-frame press. The idea that I could fully raise the press ram, screw the sizing die until it abutted the shellholder and then unscrew the die a half turn (0.0357") or so. Then size a case, measure it, screw the die in a tiny amount and repeat until I achieved the dimension I was aiming for, didn't work for me. It wasn't until I read an article published in Precision Shooting Magazine and some postings on the internet that I began to understand what I was up against. Brass hardness (this is where annealing comes into play) and thickness, case lube type and application, press rigidity and operator consistency were among the variables. Based on what I had read, I decided to try a set of Redding's Competition Shellholders. Following Redding's instructions means that the bottom of the die is always abutts the shellholder (in full contact with the shellholder) when the ram is at the top of its stroke. You simply start with the +0.010" shellholder and work your way down in 0.002" increments until you achieve the dimension you're aiming for. This solved my problem. Based on my experience and IMHO, I would not expect to be able limit sizing variations to an acceptable degree (to me) on my 550. Edited April 20, 2015 by 808win Link to comment Share on other sites More sharing options...
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