300 SAUM Brass Issue

Nannyhammer

Beginner
Feb 20, 2016
35
11
All, I've been working up loads for a Remington Model 7 300 SAUM but keep having cracked necks on the brass. Brass is probably 20yrs old but unfired. First load on new cases everything looks fine. Second load results in cracked necks on almost 60% of the few cases I have fired but no obivious signs of high pressure issues. I'm using data from Nosler Manual #9 and loads are, 2.800", 64.5-65.0 grains H4350, 150 grain AccuBond, CCI 250, with R-P brass. Velocity is slower than the manual, roughly 3060fps, but tracking with what you would expect out of the 2" shorter barrel. This brass is way to expensive to only get two loads out of it. Any ideas? Is it possible this brass was never properly annealed? Thanks in advance!
 

ShadeTree

Handloader
Mar 6, 2017
2,901
1,563
I'd say annealing, but maybe nothing to do with how it left the factory, just old. I anneal old cases before sizing and firing and don't have a problem, but that's not to say there isn't an issue with your brass. But if you haven't annealed first, I'd recommend it before trying to figure out anything else.
 

Cleveland48

Handloader
Jul 28, 2015
1,939
65
I think ShadeTree is right, I figure annealing will most likely solve this issue. You can do a cheap test to see. Just use the candle method for annealing brass, and try a few out afterwards. Hopefully that will fix the issue.


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mjcmichigan

Handloader
Dec 26, 2016
2,263
29
I went through a lot of 300 WSM cases before I started annealing them. Same as Shade Tree. Always anneal before sizing.
I keep the cases on lots of 50 now. Now I deprime (universal), anneal, size, trim, tumble, load.


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