Eye,
So two barrels, two uppers, and two bolts all have compromised unlocking/ejecting. Unfired factory ammunition can go in and out of the chambers normally. Factory ammunition can also be fired, but won't eject properly.
I am now thinking it is a gas issue.
The common parts in all this are the carrier, the block and the gas tube. Maybe gas is restricted somewhere. If you turn off the gas, or fire an AR without a gas system expect to have to pry the charge handle with some effort, due to the case stuck in the chamber. Even a small amount of gas will unlock and unstick a spent case, and you can then manually work the action to eject it. But when there is no gas, cases become stuck in the chamber.
You could swap your BCG with his and see how that goes. It may be the gas key is loose but unlikely. It could also be something blocking the gas tube but again, unlikely and easily checked. That leaves the block.
Maybe the barrel's gas port is not lining up with the gas block hole. Are you pushing the block all the way to the barrel shoulder, or leaving the MILSPEC handguard gap (0.025")? Some gas blocks are machined to butt up against the barrel shoulder, and some only work with the MILSPEC gap With calipers you can measure the distance from the edge of the gas block to the centre of the hole, and then measure the barrel shoulder to the centre of the gas port and see if they are the same. Doesn't take much for the gas port and gasblock to be misaligned, and then you get what you are describing.
So two barrels, two uppers, and two bolts all have compromised unlocking/ejecting. Unfired factory ammunition can go in and out of the chambers normally. Factory ammunition can also be fired, but won't eject properly.
I am now thinking it is a gas issue.
The common parts in all this are the carrier, the block and the gas tube. Maybe gas is restricted somewhere. If you turn off the gas, or fire an AR without a gas system expect to have to pry the charge handle with some effort, due to the case stuck in the chamber. Even a small amount of gas will unlock and unstick a spent case, and you can then manually work the action to eject it. But when there is no gas, cases become stuck in the chamber.
You could swap your BCG with his and see how that goes. It may be the gas key is loose but unlikely. It could also be something blocking the gas tube but again, unlikely and easily checked. That leaves the block.
Maybe the barrel's gas port is not lining up with the gas block hole. Are you pushing the block all the way to the barrel shoulder, or leaving the MILSPEC handguard gap (0.025")? Some gas blocks are machined to butt up against the barrel shoulder, and some only work with the MILSPEC gap With calipers you can measure the distance from the edge of the gas block to the centre of the hole, and then measure the barrel shoulder to the centre of the gas port and see if they are the same. Doesn't take much for the gas port and gasblock to be misaligned, and then you get what you are describing.