I picked up a lightly used barrel off a friend of a friend and I just happened to notice while making sure my feed ramps are aligned (they’re not, I know lol)  that there appears to be dents on the chamber face and it’s ever so slightly out of round. He was parting out an upper and the upper receiver he was selling was a BCM… I know how tightly those fit so I have a hunch he might’ve used something other than a wooden dowel to tap the barrel out.

To make sure a round would even fit in the chamber, I manually dropped a round into the barrel and it went in smoothly but I had to give the barrel a light slap with my hand to get the round to unseat and fall out. My other uppers will let a round slide out by just tilting it backwards.. so the chamber on this other barrel must be out of round just enough to hold the round against gravity, but not enough to scratch the casing.

As a test, I threw the bolt in and attached it to the lower and manually racked through a whole magazine without any issue feeding or extracting and it felt smooth…

Admittedly I’m nervous to test fire this knowing there’s something wrong. Is there any reason this would be unsafe to test or am I overthinking this and it’s fine?

Chamber looks fucked to me. I'd call it junk. Probably safe to shoot, if it even chambers or extracts. But reliability and accuracy will be shit.

You could probably have that cleaned up but, at what cost? What have you got invested in this barrel? It might be better considered money spent on education. Used barrels warrant thorough inspection. 99.9% of AR builders are hacks that don't know what they are doing and think ARs are Legos for grownups. That's not that any of us are immune from mistakes. THAT wasn't a mistake, that was ignorance that caused damage.

ETA: I reckon I didn't answer the question... safe to shoot? Probably. My guess is, though, that the chamber isn't out of round as much as there is displaced material courtesy of the previous owner going Leroy Jenkins on it with what appears to have been a steel punch. If I had to predict the future, I would say that you would possibly see extraction issues as brass formed around those deformations.  I would not shoot.

Any recommendations on who/where I could send this to for this kind of work?

I have a feeling that you’re right about the out-of-roundness, I think whatever he used might’ve compressed some of the material to the side enough to essentially create a burr within the first millimeter into the chamber, but beyond that is probably fine. So, would this need to be put on a lathe and milled a millimeter or so deeper to get passed the burr?

I also believe you’re correct that if the burr exists, casings will expand around the burr shape when fired and make lock the casing, or at least create excessive friction when trying to extract.


I’m only $100 bucks into the barrel and it’s a criterion core that has less than 500 rounds through it, so personally I feel like it’s worth saving if it can be done for $150 or less… but I don’t know where to inquire about such work.

Shit can that mess.

It'll cost you in excess of a new one before said and done. If it can even be salvaged.

I wouldn't know the regional costs but if you have $100 into it and it has "500" rounds through it, and as Dano points out, it has a chrome lined chamber, it's going to be costly. I put 500 in "" because when a guy sells you a barrel that was pounded out like that, everything else then becomes suspect.

I just got set up to ream chambers and have never done it professionally. It takes about 30 minutes to set up a bolt action barrel to ream. Considering the AR barrel has to have the barrel extension removed and replaced, add 30 minutes.

A carbide reamer is about $150.
Ceramic inserts for the lathe are relatively inexpensive. Figure 30 minutes to shave those burrs off with a ceramic before reaming. In the BEST of circumstances just kiss the throat and essentially remove the displaced material near the chamber entrance. No clue how much that little bit of cutting will impact the reamer. You'll still have divots where material was displaced but no raised metal.

In my mind, the very best case, you're probably going to shell out 2 hours of smith time plus consumables. Worst case, you might also add in more shop time to reface, rough ream and finish ream, a roughing reamer to recut the chamber completely, which will be wrecked by the chrome, and additional setup timing the barrel extension and pin. The barrel would be almost like new except no chrome lined chamber.

I'm thinking there's no way out of this for less than probably $200. Mind you, I'm little more than an armorer with some fancy tools. I'm happy to provide my opinion but it's not a "professional gunsmiths" opinion. To date I've reamed 2 chambers, both bolt actions, 1 was a simple .243 Win conversion to Ackley. Nothing like this.

It looks like a bolt was used to drive the barrel out.  Look carefully at the chamber - if the damage is limited to the face of the barrel, it may only be necessary to run a reamer into it by hand to clean up the swelling caused by the divots.  I wouldn't shoot it before it's cleaned up because a case could be trapped, and VERY difficult to be removed.

I saw the pic.

I know it is a little early for Christmas, but what I would do is put that thing in a nice new cardboard tube.  Put a nice bow on the box.  Tape a note to it telling your brother in law that you appreciate him, and you are thankful he is in the family.