AR Sponsor
Joined:
Jul 2025
Posts:
6
EE: 0% (0)
AL, USA
Posted: 7/9/2025 12:33:59 PM EDT
[Last Edit: BTS1040][Edited]
| I changed out my 16in 556 barrel to a Rainier Arms 18in SS match 556 barrel with a nitride finish. Torqued it to spec and broke the threads in and it’s solid and not loose. The factory bcg has less than a 1000 rounds on it. I’ve tried multiple brands of ammo and I keep getting blown primers. One primer even got lodged in my gas key and turned my AR into a single shot. Any idea how to fix this or what the issue is? The 16in setup from the factory gave me no issues with blown primers. |
|
Originally Posted By DVCER: Possibly overgassed? No adj gas block? Or could be tighter head space, or tighter side wall conditions, to cause less blow by at firing forming to increase working pressure of round, Or, could be less than smooth chamber walls, that is causing harder pulls of spent cases, and giving the primer more room to blow out of the case on pull as well. So really, need a couple of photos of spent case at the rims, and the spent primers that have not blow out to see that amount they have flowed to side of pockets. Last one, upper off lower, BC removed, drop a live round into the chamber, tap back of it with wooden dowel so case round is tight to chamber shoulders, and aim muzzle up to see if live round drops free from chamber. Hence want to make sure bullet is not embedding during load, while will cause the same over pressure problem of working round pressures as well. |
Posted By PlaymoreMinds:
'Twas not the <cough> sweet and innocent <cough> PlaymoreMinds...
<---skips away in frilly skirts to Candyland, leaving gutters and snorkels FAR behind.
'Twas not the <cough> sweet and innocent <cough> PlaymoreMinds...
<---skips away in frilly skirts to Candyland, leaving gutters and snorkels FAR behind.
|
Being that this is a match barrel, if it's a 223 Wylde chamber, then either it is not cut correctly being too tight, or you possibly have heavy fouling build up. For process of elimination I would highly recommend that you give it a thorough cleaning of which includes cleaning the chamber with a chamber brush and solvent to eliminate that it is not a heavily fouling build up. Then if it persists, then take a look at the fired casings to see if there are any signs that would indicate anything being out of spec for badly machined. I would also suggest that before you recut or polish the chamber, I would get a hold of Rainer Arms to see if they can provide you a replacement barrel. CY6 Greg Sullivan "Sully" WeaponsArmorer SLR15 Rifles Defensive Edge Training (763) 712-0123 |
Joined:
Dec 2025
Posts:
2
EE: 0% (0)
TX, USA
| Buy some cerrosafe from brownells. Clean the chamber and barrel very well. Plug the barrel ahead of the throat. Melt the cerrosafe and fill the chamber area. It will give you good measurement tool for your chamber. If you are a reloader or have that access. Take a fired case from that rifle and neck size the case, partially insert a projectile into the case with a seating die in the Reloading press. Put the round in the chamber (remove extractor) and close the bolt on it allowing the rifling in the throat to push the bullet into the case. Remove the bolt and carrier. Take a wooden dowl rod of appropriate size and insert it from the muzzle and lightly tap the inert round out. (may be slightly stuck in rifling) Compare that round to loaded rounds. You should see the rifling on the bullet and it should be longer in the case than a factory projectile. If you are having issues with projectiles being too long in the chamber. There are throating reamers to lengthen the throat to move your projectiles away from the lands. |
|
Originally Posted By BTS1040: I changed out my 16in 556 barrel to a Rainier Arms 18in SS match 556 barrel with a nitride finish. Torqued it to spec and broke the threads in and it’s solid and not loose. The factory bcg has less than a 1000 rounds on it. I’ve tried multiple brands of ammo and I keep getting blown primers. One primer even got lodged in my gas key and turned my AR into a single shot. Any idea how to fix this or what the issue is? The 16in setup from the factory gave me no issues with blown primers.   Maybe check and have it throated for 5.56. |
AR Sponsor