185 Juggernaut .308 OCW

[richardca99]

I'm hoping to get some feedback on this OCW test. Gun was a M700 5R with NF ATACR that has been a consistent 0.5 MOA gun with the 178 A-Max and 43.6g of Varget. Brass has been fired many times, and it gets annealed and then hit with a body die and collet die as its normal treatment. My goal is to find a good, efficient load that'll work well to 1,000 yards for target shooting (I do have access to that range).

This test was run from left to right, top to bottom. All are four-shot groups. Unfortunately, I got no data for the first group, as my chrono wasn't triggering initially. A couple of things jump out at me: There's a scatter node at 42.4g (top center group). As is common, the best accuracy came 1-2 charges above that scatter node. Even with the scatter node, it appears that POI was pretty constant from 42.4-43.2, and then it shifts down a bit from there. So my question is...

- Would you call 42.8g a node focus there (assuming it repeats)?

- Or, seeing that SD actually dropped a bit at the top charge of 43.6, would you retest from 42.8 up to about 44 or so to see what I'm missing? 43.6 is giving me about 2620 fps.



This is a graph of the velocity increase per charge weight. As you can see, it's pretty linear, and it's not yet begun to taper off.

 

[eric32]

your area is 43.0 right in the middle of those two groups. it will also give you 15fps on either side to give you some room for enviorment changes.

 

[T-shooter]

It it were me, I'd run from 42.6 to 43.0 in 2/10 increments with a minimum of 5 shots and then narrow it down to 1/10 each side of the best with at least a 10 shot group to confirm, 20 shots would be better. Is this at 100 yards? My most accurate 168 grain loads shoots best at the same velocity, about 2,570 fps.