DiRTY DOG
Well-known member
New BHW 6x6.8 barrel on a proven upper/lower. Empty upper cycles fine. Loaded, it cycled fine the first dozen rounds. Then the bolt started failing to close all the way on the first round, it would stay open 1/8 inch. I was not riding the charging handle forward.
Ammo is pulled FC brass, Redding bushing die, 58 Vmax and 55 NBTLF. All loads about 10-15 thousandsths off the lands.
First time I didn't notice and got a "click" when I pulled the trigger. The charging handle was REALLY hard to pull back, the live round was really stuck in there!
It happened several more times, same thing. Some rounds would fully seat if I pushed hard on the forward assist, others would not. It got worse and worse the more rounds I fired.
After 25 rounds in the new barrel, the bolt would not close no matter what. I banged up my knuckles yanking the charging handle open repeatedly. It "felt" like the chamber was too narrow?
1. Bolt was lubed, is not new. Cycles great w/out bullets.
2. Gas tube apprears aligned fine
3. Ejection is at 4 o'clock, bolt holds open on last shot.
4. Head space seems fine, fired shoulders measure 0.004" more than loaded.
5. Adj gas block adjusted so the bolt just holds open on the last round.
6. Case length is within spec.
7. Bullets are 10-15 thou off the lands.
Any ideas? Tight chamber?
Ammo is pulled FC brass, Redding bushing die, 58 Vmax and 55 NBTLF. All loads about 10-15 thousandsths off the lands.
First time I didn't notice and got a "click" when I pulled the trigger. The charging handle was REALLY hard to pull back, the live round was really stuck in there!
It happened several more times, same thing. Some rounds would fully seat if I pushed hard on the forward assist, others would not. It got worse and worse the more rounds I fired.
After 25 rounds in the new barrel, the bolt would not close no matter what. I banged up my knuckles yanking the charging handle open repeatedly. It "felt" like the chamber was too narrow?
1. Bolt was lubed, is not new. Cycles great w/out bullets.
2. Gas tube apprears aligned fine
3. Ejection is at 4 o'clock, bolt holds open on last shot.
4. Head space seems fine, fired shoulders measure 0.004" more than loaded.
5. Adj gas block adjusted so the bolt just holds open on the last round.
6. Case length is within spec.
7. Bullets are 10-15 thou off the lands.
Any ideas? Tight chamber?