6.5x284 load development

7MMMagnum

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Developing a load for my 6.5 x 284. Decided on Lapua Brass, H4831sc powder, Fed 210 primers and Berger 144 gr bullets loaded to start at .010 off lands. Did a ladder test and then an OCW test and found 2 nodes, one at 50.8 gr/2880 FPS and the other 52.2 gr./2970 FPS. The 52.2 gr posted a .282” at 100 yds. The 50.8 a .320 at 100 yds. So I decided to do a 5 shot group at 300 yds with the 2 load nodes to see how they grouped. Now I am kind of perplexed. The 50.8 shot 2” vertical x 1” horizontal. The 52.2 shot 1” vertical x 2” horizontal. I shot in gusty wind conditions because I figured both groups would string horizontally with the wind. Can anyone explain why the slower bullet might not string horizontally as much as the faster load. Or how do I read this to pick a node to stick with.
 
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The group size could be coincidental. I would select 52.2 because it shoots faster and it proves to shoot accurate. I would test 52.0 and 52.4 and see how they both shoot. If they do well, then stick with 52.2gr and test it a few more times to verify it’s consistency.
+1 to that! You have great findings already. Going .2 either way will certainly help you know the best charge weight. Then run a seating test. That should tighten up an already fine shooter.
 

7MMMagnum

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+1 to that! You have great findings already. Going .2 either way will certainly help you know the best charge weight. Then run a seating test. That should tighten up an already fine shooter.
In your opinion, should I be concerned with pressure increases due to less case capacity as I seat deeper while performing a seating test. I have read that some folks do the seating test first with reduced loads and others find the nodes and then fine tune with seating.
 
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At .010 off the lands you should have plenty of room to see the seating nodes tightening and opening. We always need to be diligent in studying the available pressure signs during load development at our ranges during and stop when we see them. Log your CBTO and work back in 3-4 shot groups in .005 or .010 Increments until you find an acceptable group for you. My 140 Berger hybrids and Lapua with H4831sc have always been good from .060 to .020 and have been safe in my 6.5x284. I actually am using 52.2grs with this barrel.
 

338 dude

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EF90921B-816C-4D99-BD18-F844FEB5ACCB.jpeg

.010 jam 2980 fps 140 VLd hunting
 

7MMMagnum

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That is some fine shooting “338 dude”. I have pics of the target I did my OCW test with. I did it round robin cleaning every eight shots because rifle is new. Pleased with the 100 yd accuracy but would like to tighten up at longer range. It was calm with very little wind on the test.

We must have hit the same node Longbarrel 1890. Next on to do another OCW with seating depth. Thanks for all the feedback.
 

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nksmfamjp

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To me, 6 and 7 needed tested at 300. As for what you shot at 300, it seems like you held wind better on the one group, but the lower vertical should be the keeper.

probably need to see some 5 shot group consistency.....I like 5 groups of 5 at 100. That will give you a real sd and how consistent groups are.
 

7MMMagnum

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Thanks, I certainly plan on doing that. To be honest in retrospect I should not have shot on that day. The wind was blowing diagonally at 10 to 15 mph with gusts up to 25. True hunting conditions but not anywhere close to being conditions for working up a load. Since I had my Chrony thought I would shoot anyway to get some MV numbers and see how the 144’s shot in the wind. Was a real surprise to see how the groups reacted though. Was kind of dumbfounded to see one string vertically and one string horizontally. I was doing round robin and placed my truck to block the wind on the bench so I could hold. I am planning to take everyone’s advice here and narrow in on that 52.2 and 52.6 load then work on optimal seating depth. Great advice from all and really appreciated.
 
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