Author Topic: 7MM WSM cratered primers  (Read 243 times)

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Offline ejpaul1

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7MM WSM cratered primers
« on: July 11, 2010, 12:49:03 PM »
I have been shooting htis 7MM WSM for 4 years now and like it plenty. Except, I get cratred primers with nearly any load. Actually I have shot other powders through it long ago but dont remember any cratering issues. I probably didnt even know about it. ANyway, I have been using magpro powder below the max charge most of the time and it doesnt seem to matter. I have reduced some loads to safe minimums and it still craters primers. I am going to try a few with H1000 and some H4350 and see if the results are the same. The accuracy and velocity are right what I want but these cratered primers still leave a question.

I load my 06 to the max with H4350 and as well 243 with the max powder charge and dont get any cratered primers.

I was getting 3300 and change out of a hornady 139 grain sst with 73 grains of the magpro which is less than the max. I reduced the load to 69 grains and was still getting cratered primers. Any ideas?

Offline stimpylu32

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Re: 7MM WSM cratered primers
« Reply #1 on: July 11, 2010, 01:18:43 PM »
2 things I would look at are the headspace of the rounds and also the area around the firing pin , improper HS can cause the case to move back during firing and cause this , so too can wear around the firing pin .

stimpy
Deceased June 17, 2015


:D If i can,t stop it with 6 it can,t be stopped