Problem with AR15

[Aces and 8s]

So my brother built an 80% a couple years ago and it has worked out just fine for him. He recently called me over because he was having a problem with it, and wanted me to take a look at it.

He said during his recent move from one apartment to another, he dropped the rifle (while in it's soft case) during the move. He didn't think anything of it at the time. After he was all settled in his new place, he was going to take a trip to the range, so he wanted to lube the rifle. However, when he went to check if it was loaded, he was unable to pull the charging handle back, or move the carrier group.

So, I come over to look at it. Magazine drops fine, but I cannot pull the charging handle back, the carrier group won't budge. I pushed the forward assist and the carrier group moves forward a little, but still, it won't budge when the charging handle is attempted to be pulled back.

As far as I can tell, the rifle isn't loaded, so I remove both assembly pins and have no issues separating the upper from the lower. I inspect the lower, and everything APPEARS ok.

So, I move to the upper. With the upper and lower apart, I was able to remove the charging handle and carrier group without issue. After inspecting the charging handle and carrier group, I don't notice anything out of place. So, I lube everything up and put it back together. Again, doesn't budge. With unnecessary force, I am able to move the carrier group, but it feels very gritty and moves very slowly.

I am at a loss and not sure what could be up with his rifle.



Thoughts?

Edit: This is a piston setup, FWIW.

[Junkie]

If the buffer tube isn't in line with the upper that would explain it.

[SteveRogers]

Without looking at the rifle, it appears your brother bent the buffer tube. If there are any kinks or bends in the buffer tube, the bolt carrier may have a hard time moving back and forth. Just a guess at this point

[Milsurps]

Take a hard look at the Buffer tube assembly.

[Eastwoodfan101]

Sounds like he may have a bent buffer tube. or a misaligned buffer retainer.

[HighWildFree]

Anyone suggest looking at the buffer tube assembly?

[Aces and 8s]

Buffer tube. What is that?

J/K.

Didn't even think to check that, I'll give it a look.

[felimen]

Why would a bent buffer tube not allow you to charge the gun,


Cannnnn youuuu diiig iiiiiit !

[ZombieLivesMatter]

Just as everyone above said if he dropped it he could have bent the buffer tube. Since you already removed the upper assembly, and you're able to remove the charging handle and bolt carrier group no problem that's a clear sign.

[Lonestargrizzly]

If he dropped it on the carpet, he's screwed.

[Predator]

Are buffer tubes pretty weak, or was this a MAJOR drop?

[Junkie]

I don't think I've heard of a bent tube before. I have heard of a cracked lower where the tube attaches, though...

[HardwoodRods]

Well I guess it could be a bent buffer tube or a damaged shoulder thing that goes up

[LeadFarmer74]

Why would a bent buffer tube not allow you to charge the gun,


Cannnnn youuuu diiig iiiiiit !

Is this a serious question? To the OP make sure the buffer asembly moves freely without the upper on it.

[Christopher761]

I agree that the buffer tube needs to be looked at. Make sure the buffer moves freely against the spring in the tube. I really doubt that the tube is bent, as those are really tough. If it is, it should be obvious.

Also check the lower receiver where the buffer tube connects to the lower receiver. If that is bent, then the bolt carrier can't push back the buffer in the tube. If the lower receiver is bent, buy a new one, and move all of the parts over.

Pictures?