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Discussion Starter · #1 · (Edited)
Gents,

I am reloading for my 7/08 bolt action rifle. I have measured my cases to the datum line with my comparator gauge. I de-primed the fired cases and here are the measurements for five fired cases: 3.631, 3.631, 3.631, 3.631, and 3.631.

Here are the measurements for five unfired cartridges that are loaded from the factory: 3.631, 3.628, 3.627, 3.627, and 3.628.

Now, I have set up my dies and I started resizing, aiming for .002 shoulder set back. In my testing, I measured one case at 3.625. That is .006 for shoulder set back. I am working on .002 but a few did not make that number.

Here is my question: What number is considered excessive? Is .006 in the danger zone?

I read that ARs use .003 to .005 for proper feeding and reliability.

TC
 

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mongo, it looks like you deprimed the fired cases before you took your shoulder measurements which is a good thing and provides more measurement consistency. Your factory ammo has the primers in them. A primer that is a proud, even a thou or two can change your shoulder measurement. I do not remember for certain what is excessive headspace but I don't believe 0.006 is too much. I had some new 6.8 brass that was 0.017" on the shoulder and they fired ok. I had one 6.8 barrel that had a chamber 0.008" longer than my other 6.8s and it pierced primers frequently compared to the others. I had another rifle with 0.025" of headspace. I found that out after the case separated and was stuck in the chamber.

I try and load my bolt actions with 0.001" setback, just so a slight drag can be felt when the bolt is closed. Over the years, I changed to 0.002" set-back as some brass has a little spring back.
 
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