Reload dilemma

[limbic]

6BRX
105 Scenar
RL15
All loads jammed .015 in the lands
Range 200y
All 3 shot groups

I was working up a new load today. I have several different powder charges from 32.4 to 33.8. .2 grain increments. I found three loads that peaked my interest.
32.6g yielded a .82 group with a ES/SD of 7/4; MV 2940 Most of the .8 was in vertical
33.0g yielded a .33 group with ES/SD 14/7; MV 2980. ZERO vertical. Three perfect horizontal holes
33.8g yielded a 1.02 group with ES/SD 7/4; MV 3030. .6-.7 vertical.

My plan was to load each charge again. Five this time not three rounds per charge. I'd also load a group .05 longer and .05 shorter and see where that takes me.

Should I just focus on the low ES/SD groups? Or maybe just load up 10 of the small group and see how it does at 300. Ideally I'd do it all but what would be a wise first step.

 

[Mikem]

I think you have to small of a sampling size to make changes based on your ES/SD readings, some will say even 5 is to small, and prefer 10 round.
At first, I like to keep things simple, and would go with the tightest group, working the bullet in and out, more out than in. Sometime a little jump is good, so dont be afraid to try it. And if you get to much of a jam, it may just be shoving the bullet back in the case, but you can test for this.
I would load 5 or 10 of anything that looks promising, and study those numbers, and group size.
Good Luck.

 

[Laurie]

I think you have to small of a sampling size to make changes based on your ES/SD readings, some will say even 5 is to small, and prefer 10 round.
At first, I like to keep things simple, and would go with the tightest group, working the bullet in and out, more out than in. Sometime a little jump is good, so dont be afraid to try it. And if you get to much of a jam, it may just be shoving the bullet back in the case, but you can test for this.
I would load 5 or 10 of anything that looks promising, and study those numbers, and group size. (Posted by Mikem)

+ 1 on that. Initial 3 round test groups tell you three things - rough grouping capability; approximate MV; what the pressure indications say. From these you can determine likely 'sweet spots', whether the velocity is roughly what you're looking for, and whether pressure signs say that load is low, average, or on the 'hot side'. From there, you can fine-tune your loads with five-round groups around the 3-round examples that did well, and/or move charge weights up/down if MVs aren't suitable, or you have signs of excessive pressure etc.

Your 33gn 0.33" horizontal group at 200yd looks very promising, as unless you shot in an absolute flat calm, you'll likely see some wind effect at this range. So, you could try 5 rounds batches around that charge weight in 0.2gn steps, maybe 32.8 - 33.4gn to see how they do. Then after that, try seating depth changes to the closest grouping load. Only change one variable at a time - that is don't vary charge weights and seating depths together.

Unless you plan to shoot at very long ranges, the ES of 14 is acceptable, but as Mikem says you need a much larger sample size than 3 rounds to know what you're really getting. A five or ten round string could be pretty similar or two or even three times as large.

Laurie,
York, England

 

[brxbrad]

Brx Testing done this weekend. Tests consist of 105 Berger VLD, 108 Berger, 107 MatchKing. Loaded 20 rounds per bullet, 4 powder weights per bullet from 33.2 thru 33.8 , making 5 rounds per group. COAL @ OJ the same for each. Just touching the lands for all.
Shooting newly configured BRX with Savage Action, Kreiger 1:8 twist, 28 in barrel, .272 neck. What a sweetheart. Best results: 107 MK, 33.4 and 33.6 Varget. Group Size .557 @33.4@ 200yds and .5 @33.6 @ 200yrds. Next was the 105 Berger VLD, same configuration, Group Size .5 @ 33.2 with slight pressure signs. I didnt get to finish the 105 test but expect it to do well @ 33.0 or 32.8. I've use Varget pretty much all the time as RL 15 seems to be temp. sensitivity.

 

[brxbrad]

Oh....The 108's sucked pretty much with

Group Size 1.05 1.315 1.19 0.715
Std Dev 6 7 13 10