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Inconsistent Results with Same Charge Weight

dtsmith9

Private
Minuteman
Aug 25, 2019
4
0
Hey guys, I'm developing a load for my 300WM. Currently working with Hornady brass, ELD-M 208grs, H1000, and Winchester primers. During my initial ladder testing, I found 73.5, 74.5, and 77.0 to be the best charge weights. But, when I loaded up two, 3-shot groups for each of those three weights for verification, my results didn't make much sense. For the 73.5 and 77.0gr sets, one group was less than half an inch and the other was over 1.5" (not two tight and one flier, but three evenly spaced). Both 3-shot groups for 74.5gr were under an inch, but neither were better than the smaller groups from the other two sets. Are these results telling me that 74.5 is the weight I should fine tune from, or is there something else going on?

These results are from 2x fired brass, with the following measurements - base-shoulder 2.270, trim-to- 2.610, and CBTO 2.881. Now because this is a factory Remington 700 LR, I am jumping about 0.2" - not much I can do about that. However, how can I get one 3-shot group at 0.210" and the next group, with the exact same dimensions and loading methods, be closer to 2"?

Thank you for taking the time to read, and I look forward to your responses.
-Troy
 
My thoughts, use a ladder test or velocity ladder (Satterlee 10 shot method) to determine a stable powder charge, then test seating depth to tighten groups.
 
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My gun likes 3.660” which used to be .020” off

I dunno where you’ll hit the lands
 
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