The upper is/was a CMMG/DPMS Flat top Upper, 1:7 twist, 14.5” barrel with vortex permanently attached, purchase about 2 years ago.
Had a brand new(2 years ago) RRA BC/B mated with it. Shot about 2k+ rounds through it flawlessly. Most of them were wolf polymer and never had a problem. They all ejected and shot it for over a year with no problems. As I had shot the same batches of ammo through 2 other AR’s as well.
A couple of months back had a major jam in it. Another guy was shooting it and it didn’t eject the spent shell. Well he loaded several mags into it without checking to see if it was clear and kept ramming another shell into it while the spent one was still in it. long story short…Tried everything to knock the shell out, bent a few rods etc.
I had to have the upper removed from the barrel. Then had to drill the spent casing out of the barrel.
Then I sent it the barrel to Adco and had Steve install a brand new RRA A4 flat top upper to the DPMS/CMMG barrel, bought a new BC/B with the crane d-ring installed as well to basically complete the upper again.
Received the upper with brand new BC/B, slapped it on my lower and went to the range. A new batch of ammo loaded (wolf polymer) in a group of random mags. Was shooting one of my other AR’s just fine.
Inserted a mag into the gun and pulled the trigger. ONE SHOT. That’s it. It didn’t eject the shell. I tried to clear it manually by using the charging handle. Then went to the buttstock on the ground method. That didn’t work. Then tried to rod it out to the point where I bent the cleaning rod. I let it cool, put lube in it from the muzzle and from the chamber, kept trying to rod it.
And it’s still stuck.
What could be causing this to jam to this extent that a rod wont knock it off? Is there something wrong with the chamber or the barrel?
The fact that I have fired 2k+ rounds of wolf through it, and then all of a sudden jams like a rock, baffles me.
Any ideas to remove the casing and what to check to prevent further jamming?
Edit: When i was trying to knock the casing out, i had already removed the upper from the lower and had removed the BC/B as well, so it was an empty upper.