I’m working a load for a custom built .300 AAC Remington 700. The barrel is a 16” Bartlein 1/7 twist.
I have found some inconsistencies with muzzle velocity, and I’m working hard to understand the problem.
I suspect the issue may be with neck tension, and inconsistencies between neck wall thickness and brass hardness.
I separated my brass and loaded all same headstamp brass with 220gn Berger Hybrids, and 10.5gn CFE BLK. Projectiles were set .010” off the lands. With this load, I was able to manage barely 1 moa five shot groups. I may also try them kissing the lands as well.
Using brass made from 5.56 lake city cases, the best I can do hovers around 2 moa.
I have since ordered a few hundred 223 Lapua cases, neck turning lathe, neck sizing die, as well as a Redding bushing die.
Please let me know if you guys think I’m off track. The reason I think neck tension is the issue is because of the variable resistance I see when seating projectiles. Is there anything else I can do to ensure consistent neck tension? Would crimping be a good option? I just hate to crimp for a bolt gun.
And, of course I could be going down the wrong rabbit hole here..... I’ve tried multiple Bullets and found that the Berger 220gn hybrid and Sierra 220gn bthp shoot the best so far....so I’ve been trying to develop a load with those two.
Thanks so much in advance!
Happy New Year!
I have found some inconsistencies with muzzle velocity, and I’m working hard to understand the problem.
I suspect the issue may be with neck tension, and inconsistencies between neck wall thickness and brass hardness.
I separated my brass and loaded all same headstamp brass with 220gn Berger Hybrids, and 10.5gn CFE BLK. Projectiles were set .010” off the lands. With this load, I was able to manage barely 1 moa five shot groups. I may also try them kissing the lands as well.
Using brass made from 5.56 lake city cases, the best I can do hovers around 2 moa.
I have since ordered a few hundred 223 Lapua cases, neck turning lathe, neck sizing die, as well as a Redding bushing die.
Please let me know if you guys think I’m off track. The reason I think neck tension is the issue is because of the variable resistance I see when seating projectiles. Is there anything else I can do to ensure consistent neck tension? Would crimping be a good option? I just hate to crimp for a bolt gun.
And, of course I could be going down the wrong rabbit hole here..... I’ve tried multiple Bullets and found that the Berger 220gn hybrid and Sierra 220gn bthp shoot the best so far....so I’ve been trying to develop a load with those two.
Thanks so much in advance!
Happy New Year!