07-31-2018, 03:52 PM
JK81 you may have a couple different issues so it best to make one change at a time to try and isolate the problem. The photo of the spent brass shows very light primer indentations. I’d suspect your Elfman trigger/safety is not adjusted correctly as Whit indicated. On a standard milspec hammer it is very easy to improperly install the hammer spring which contribute to light strikes. Sounds like the Elfman trigger group your using is installed as a complete unit so it is not likely to have the hammer spring improperly installed.
Like Whit mentioned I’d take the upper off the lower and see if the bolt and carrier move freely. The bolt and carrier should be wet with lube like Slip 2000, Breakfree CLP or synthetic motor oil. If the BCG does not move freely inspect the carrier key for wear. The gas tube might not be properly aligned with the carrier key. The gas tube or carrier key might show finish wear if not properly alligned. If the rifle is not ejecting a spent brass the gas block may not be properly centered over the gas port.
If everything in the upper appears normal I’d find someone with a proven lower. I’d put your upper on their lower and check for function. Load one round into the mag. Using the charging handle charge and fire the weapon. Spent brass should eject cleanly and bolt should lock to the rear. If the bolt is not held by the bolt catch this generally indicates the rifle is undergassed. The gas block is likely not centered over the gas port, wrong size gas port or to heavy a buffer. Grendel Hunter used to use Satern Liberty barrels which were known for having large gas ports. I’d suspect the gas block needs adjusted.
If the rifle fires the round ejects and the bolt catch holds the bolt try two rounds. If the rifle functions with two rounds try three rounds. If the rifle will function with three rounds you know the rifle is capable of feeding from both sides of the mag and there appears to be adequate gas. I’d then add a few more rounds to the mag and fire a few more rounds. The location of ejected brass can indicate if the gun is over or maybe under gassed. If the rifle is under gassed the brass may dribble out. Over gassed AR’s generally eject to 1-2 O clock. If the gun fails to feed with more rounds in the mag this can indicate a mag problem, a timing/gas issue or failure to feed (ejector problem).
Another issue is the ejector can interfere with chambering rounds on larger case head cartridges in the AR-15. If you are encountering failure to feed the ejector can cause feeding issues. Here is a link describing a mod to a ejector to improve feeding.
http://bulletin.accurateshooter.com/2014...artridges/
When testing a new rifle I try to use a proven magazine with factory ammunition. I’d also remove the bolt/carrier from your upper and try to drop a hand loaded cartridge into the chamber. Push on the base of the cartridge to ensure it is seated in the chamber. Raise the muzzle and the cartridge should fall out. If the round will not fall out of the barrel use a cleaning rod to push out the cartridge. The bullet could be seated to long and is pushed into the rifling. You can color the nose of the bullet with a black marker to see if the bullet is into the lands (reinsert color bullet into chamber). Another problem with hand loaded ammo is not completely full length resizing the brass. The shoulder of the brass needs to be bumped back .003-.005 to fit into the chamber properly. If you have a factory cartridge drop it into your barrels chamber. Raise the muzzle and if the factory round will not fall out of the chamber the chamber might be out of spec.
Like Whit mentioned I’d take the upper off the lower and see if the bolt and carrier move freely. The bolt and carrier should be wet with lube like Slip 2000, Breakfree CLP or synthetic motor oil. If the BCG does not move freely inspect the carrier key for wear. The gas tube might not be properly aligned with the carrier key. The gas tube or carrier key might show finish wear if not properly alligned. If the rifle is not ejecting a spent brass the gas block may not be properly centered over the gas port.
If everything in the upper appears normal I’d find someone with a proven lower. I’d put your upper on their lower and check for function. Load one round into the mag. Using the charging handle charge and fire the weapon. Spent brass should eject cleanly and bolt should lock to the rear. If the bolt is not held by the bolt catch this generally indicates the rifle is undergassed. The gas block is likely not centered over the gas port, wrong size gas port or to heavy a buffer. Grendel Hunter used to use Satern Liberty barrels which were known for having large gas ports. I’d suspect the gas block needs adjusted.
If the rifle fires the round ejects and the bolt catch holds the bolt try two rounds. If the rifle functions with two rounds try three rounds. If the rifle will function with three rounds you know the rifle is capable of feeding from both sides of the mag and there appears to be adequate gas. I’d then add a few more rounds to the mag and fire a few more rounds. The location of ejected brass can indicate if the gun is over or maybe under gassed. If the rifle is under gassed the brass may dribble out. Over gassed AR’s generally eject to 1-2 O clock. If the gun fails to feed with more rounds in the mag this can indicate a mag problem, a timing/gas issue or failure to feed (ejector problem).
Another issue is the ejector can interfere with chambering rounds on larger case head cartridges in the AR-15. If you are encountering failure to feed the ejector can cause feeding issues. Here is a link describing a mod to a ejector to improve feeding.
http://bulletin.accurateshooter.com/2014...artridges/
When testing a new rifle I try to use a proven magazine with factory ammunition. I’d also remove the bolt/carrier from your upper and try to drop a hand loaded cartridge into the chamber. Push on the base of the cartridge to ensure it is seated in the chamber. Raise the muzzle and the cartridge should fall out. If the round will not fall out of the barrel use a cleaning rod to push out the cartridge. The bullet could be seated to long and is pushed into the rifling. You can color the nose of the bullet with a black marker to see if the bullet is into the lands (reinsert color bullet into chamber). Another problem with hand loaded ammo is not completely full length resizing the brass. The shoulder of the brass needs to be bumped back .003-.005 to fit into the chamber properly. If you have a factory cartridge drop it into your barrels chamber. Raise the muzzle and if the factory round will not fall out of the chamber the chamber might be out of spec.