HodakaGA
09-29-2012, 09:14 PM
Update: 10.6.12
I finally worked up loads for my AR15 in 300 AAC Blackout and tested them today.
16” AR Stoner stainless barrel with carbine gas.
311299 from NOE group buy cast from 50/50 COWW and mostly pure plus 1.5% tin. They weighed, on average, 204 grains before I seated a gas check and sized them .309 with a Lee push-thru. They were lubed w/thinned Lee Alox before and after sizing.
Standard carbine spring and weight with a FA bolt carrier.
OAL at 2.19” and used a Lee FCD to remove case bell.
Mixed factory and LC brass all trimmed to same min. length. WSR primers.
Results with WW680 powder:
Load Average velocity SD
13.5 1441 20
14.0 1468 24
14.5 1530 21
15.0 1552 19
15.5 1575 14
10.6.12 Update:
Same as before only 2.18 OAL
Load Avg. Velocity SD
15.5 1621 8.6
16.0 1657 11.7
16.5 1667 16.5
Primers show no sign of excess pressure.
For giggles I had loaded some with Varget. It seemed 16.6 was going to be about 100% load with the boolit seated so that was my load. The result was 1194 fps and a SD of 48.
I didn’t shoot for accuracy (since I was using a 4 moa aimpoint clone), only function but all seemed to print pretty close to the same groups. Maybe 3-4 moa.
I fired a total of 40 rounds and had no visible leading.
The pmags I used locked back on the lowest loads but I had some failures to feed from the ribs interfering and causing the tips to dip. I gave up on the pmags and shot the rest with a Bob’s Sled.
No signs of high pressure at any level of loading. I think I have room to push these a little harder. The SD seemed to steadily drop with increased charges. Next time I'll try for more accuracy testing, the range was too crowded to run fresh targets out each time.
Warning: these loads worked as described in my rifle, your rifle may vary. Use data at your own risk.
I finally worked up loads for my AR15 in 300 AAC Blackout and tested them today.
16” AR Stoner stainless barrel with carbine gas.
311299 from NOE group buy cast from 50/50 COWW and mostly pure plus 1.5% tin. They weighed, on average, 204 grains before I seated a gas check and sized them .309 with a Lee push-thru. They were lubed w/thinned Lee Alox before and after sizing.
Standard carbine spring and weight with a FA bolt carrier.
OAL at 2.19” and used a Lee FCD to remove case bell.
Mixed factory and LC brass all trimmed to same min. length. WSR primers.
Results with WW680 powder:
Load Average velocity SD
13.5 1441 20
14.0 1468 24
14.5 1530 21
15.0 1552 19
15.5 1575 14
10.6.12 Update:
Same as before only 2.18 OAL
Load Avg. Velocity SD
15.5 1621 8.6
16.0 1657 11.7
16.5 1667 16.5
Primers show no sign of excess pressure.
For giggles I had loaded some with Varget. It seemed 16.6 was going to be about 100% load with the boolit seated so that was my load. The result was 1194 fps and a SD of 48.
I didn’t shoot for accuracy (since I was using a 4 moa aimpoint clone), only function but all seemed to print pretty close to the same groups. Maybe 3-4 moa.
I fired a total of 40 rounds and had no visible leading.
The pmags I used locked back on the lowest loads but I had some failures to feed from the ribs interfering and causing the tips to dip. I gave up on the pmags and shot the rest with a Bob’s Sled.
No signs of high pressure at any level of loading. I think I have room to push these a little harder. The SD seemed to steadily drop with increased charges. Next time I'll try for more accuracy testing, the range was too crowded to run fresh targets out each time.
Warning: these loads worked as described in my rifle, your rifle may vary. Use data at your own risk.