Load development opinions sought...

[TexasShooter59]

I am loading for AR-15, 16" length 1:7 twist barrel, 5.56 chamber. The load is Hornady 75gr BTHP (#2279), Varget, CCI#41 primer, LC08 cases.

Charges were picked based on the .223 Service Rifle data in the Hornady load book. In the following photos, the charges run from left to right, low to high. On the back/top three rows, low to high runs in order, black, brown, green, blue, red. The best loads were blue and red, so a reshoot was in order, and those are the cases in the front/bottom two rows. Hopefully, this makes sense looking at the following photos.

The charges are as follows:

Black    22.0    93.6%
Brown    22.5    95.7%
Green    23.0    97.9%
Blue     23.5   100.0%
Red      23.7   100.9%

The max load listed in the data book for Varget was 23.5 grains. If you calculate your loads for Optimal Charge Weight following their instructions, you should have one charge above max, which is where the 23.7 came from.

Oddly enough, I got a better group at 100 yards with 23.5, and a better group at 200 with 23.7. I don't really understand this unless the wind changed somehow.

So, I am interested to see what experienced folks have to say about the way the primers and cases look, and any other comments you might have. Thanks in advance!

 

[TexasShooter59]

Photo 1

 

[TexasShooter59]

Photo 2

 

[Walkalong]

Hard to say from pics of course, but nothing about those primers looks alarming at all. If case life is short, that will tell you something, but you should be OK.

One or two groups mean almost nothing.

unless the wind changed somehow.

Wind pushes bullets far more than most realize.

Load 25 of each and shoot 5 five shot groups with each, alternating between loads. That will begin to tell you something.

I can take my bench gun and shoot a .267 at 200 yards, and then shoot a .648 the next group, no problem at all. The only difference is conditions. Wind, mirage, etc. And of course technique can bite us in the butt at times.

 

[Searcher4851]

Hard to tell for sure from the pics, but don't really see any signs of excessive pressure.

According to Hodgdon, max load with a 75 grain bullet and Varget is 25gr which would be a compressed load. Their starting load is 22.5gr. They don't indicate what they shot that out of though. I

f you're using the Hornady 9th edition, they seem to have gotten a bit more conservative on several loads I've seen.