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TREERAT
04-28-2009, 11:32 PM
I have COMPLEATLEY solved the blow back on my cases!!!
I had been trimming .358 win brass and others formed into .358 win. .010 less than sami spec of 2.015 so trimed to 2.005 and was getting BAD blowback on all the necks, it is now solved.

how I did it was form a 30-06 case and leave the neck long, about 2.050 then I trimmed .001 off at a time until the bolt handle would just close down with light thumb preasure, which came out to EXACTLY 2.040 - then when fire formed to blow sholder out to proper diameter the case shortens aprox. .007 - then when neck sized, due to the expander drag they come out at 2.039 - perfect fit for length! bolt cycles just like factory ammo. I also flared the cases a little more than usual and left the flare on the loaded rounds. so in essence I am head spacing off the sholder and case mouth atthe same time!

only thing I will have to do is be verry careful and check the length every time I load. so with the trimmer set correct I will just run them through the trimmer after every time I size, and all should be right.

:-DNECK BLOWBACK PROBLEM SOLVED!!!:-D

Calamity Jake
04-29-2009, 08:41 AM
After fire forming the case mouth will not be square and needs to be retrimmed a might, just enough to square them up.

Forming cases from other cases work hardens the brass so annealing before and or after is a
good idea, plus it helps stop blowback

Just something else to think about!!

TREERAT
04-29-2009, 11:42 AM
only had to trim .001 to square. on the longer cases I cut them off in the middle of the sholder, then anneal, then size form, then trim, then load and fireform, then neck size and check trim, square up, and load again. I asume since I am flaring to load then removing the flare when neck sized that is alot of working the first 1/4 inch of the neck, and therfore would probably be a good idea to anneal about every five loads to make my brass last as long as possible.