Very stuck barrel in upper receiver

[Greenbug]

Throw it in the deep freeze overnight and try it the next morning.

If your in over your head. Sell the upper complete and buy a new barrel?
Or keep fixing it till all is broken?

Beat me to it!

 

[IronMonster]

I know there are different penetrating oils. All I have around is PB blaster. Any reason not to use this?

panther piss is fine, you just need something that will get in and help break the surface tension to facilitate movement.

 

[DLS]

I know there are different penetrating oils. All I have around is PB blaster. Any reason not to use this?

KROIL is my go to for this. It claims to penetrate gaps as small as 0.0001.

PB blaster is good but it loses out to KROIL in a few YouTube documented experiments from the likes of ChrisFix etc. (Yeah, the height of scientific method, I know. But the methodology is really not that bad).

I would let it soak for a few hours, hit it with a torch and reapply while hot. After a few cycles if it's still stuck the try the freezer overnight.

If after a couple of rounds of the heat / freeze cycle it's still stuck some type of press is in order.

FWIW

 

[IronMonster]

Kroil is great stuff and probably the best penitraing oil out there, however at 20 times the cost of Pb blaster I don't use it much.

I would use what you have

 

[Capn Jack]

I read a study one time about penetrating oils. Several brands were tested against some home remedies
and the winner was.....
A mixture of Acetone and ATF.

 

[Jcon268]

Put the barreled upper in the freezer overnight. It will pop out relatively easy in the morning. The cold makes the metal contract (shrink).

I considered this but since the barrel and upper are both being frozen, wouldn't the aluminum receiver shrink down around the barrel making it grip even tighter? I'm not incredibly versed in thermodynamics.

 

[Jcon268]

I tried a small amount of PB blaster and it didn't seem to hurt the finish at least immediately. I wiped the excess off to be sure. If the barrel is loctited, wouldn't an acetylene torch be sufficient to break it loose? I'd really like to keep this barrel. Again not worried about the upper too much but it's a 14.5" high quality barrel with a specific brake pinned and welded that accepts a suppressor. Would be a pretty big loss to have to sell and start over.

 

[DLS]

I considered this but since the barrel and upper are both being frozen, wouldn't the aluminum receiver shrink down around the barrel making it grip even tighter? I'm not incredibly versed in thermodynamics.

Aluminum and steel contract a different amount and at differing rates. Several freeze / thaw cycles may in and of themselves loosen the barrel enough for removal. If not the movement at the joint may help penetrating oils and the like to get in and do their magic.

As ron stated earlier the OP may have a glued in barrel, if so heat will be necessary otherwise you will need to crack the adhesive with a large amount of pressure.

I hear you IronMonster regarding the cost of KROIL, but when you do only need drops on the joint to make it work, so a small container can last a very long time. I use a couple of chemistry pipettes to place the KROIL. The are long to get into tight places and allow the tiniest of drops to be placed exactly where you want them. Don't get me wrong, I use PB Blaster too. When I'm under a car trying to free rusted exhaust bolts I'm going to just grab the rattle can and spray away.

 

[HB of CJ]

Are we talking about an AR15 upper receiver with a "stuck" barrel? With the barrel nut loosened? If so, then ...

1) Determine if your barrel extension is not cracked. Sometimes it happens. If so you can manhandle the barrel without regards to salvage.

2) I think somebody here already nailed it and thank you. Deep freeze. Like minus 10F. Wrap up and leave overnight. Wrap it so the stink does not transfer to any good food in the deep freeze.

The aluminimuimm upper will contract less than the steel barrel. This might create a temporary condition where the barrel can be locked down into a good 5-6 inch bench vise and the upper tapped off GENTLY using a soft hammer. Do not hit too hard. You can crack the upper.

We used to build precision AR15 rifles and sometimes the barrel did slide very tightly into the threaded area of the upper receiver front. Good for accuracy. But the barrels were seldom removed once indexed and torqued up properly.

Good luck.

hundreds of builds. uncounted rebuilds.

 

[Jcon268]

Are we talking about an AR15 upper receiver with a "stuck" barrel? With the barrel nut loosened? If so, then ...

1) Determine if your barrel extension is not cracked. Sometimes it happens. If so you can manhandle the barrel without regards to salvage.

2) I think somebody here already nailed it and thank you. Deep freeze. Like minus 10F. Wrap up and leave overnight. Wrap it so the stink does not transfer to any good food in the deep freeze.

The aluminimuimm upper will contract less than the steel barrel. This might create a temporary condition where the barrel can be locked down into a good 5-6 inch bench vise and the upper tapped off GENTLY using a soft hammer. Do not hit too hard. You can crack the upper.

We used to build precision AR15 rifles and sometimes the barrel did slide very tightly into the threaded area of the upper receiver front. Good for accuracy. But the barrels were seldom removed once indexed and torqued up properly.

Good luck.

hundreds of builds. uncounted rebuilds.

Yes it's a stuck AR15 barrel. Purchased this upper new. It has sat for awhile at my house but never been fired as I haven't had time to do any outdoor shooting lately. In that time it sat, I got antsy and decided to replace the upper receiver (also gives me something to do). If it proves to be too much trouble, I may reassemble and sell it. I have a fair amount of money into this upper, I'd hate to take a loss and start over but if I have to cut my losses I'd like to avoid damaging the barrel also. What size wood dowel to pound out from the inside?

 

[Jcon268]

By the way my vice is a 15 minute drive away from my freezer

 

[HB of CJ]

Have a buddy physically hold the barrel. Use thick gloves. The barrel will be minus 10F or so for a little bit of time. This method will have to be done right by the deep freeze ... if you have a deep freezer.

He holds the barrel. You tap with a soft hammer. Tap on the carrying handle. Tap around the front. If you do not have a carry handle just tap all around as close as you can to the barrel. Do not smack.

A wood dowel or hard wood smacker sounds like a good idea. Easy to ding the finish.

If you can not get the barrel off you might want to consider having some machine shop do it for you? I do not know if a slide hammer or gear puller type gadget could be adapted. You are on fresh ground.

You might start thinking the upper and barrel are toast. None recoverable. This sort of thing does happen. I will not tell you how I know this to be true. Or keep it and consider it a thought exercise how to separate.

I have seen cracked barrel extensions lock up everything. But sometimes the upper is cracked also.

Good luck.

 

[Jcon268]

My opinion is that it can be done I just don't have the resources to do it. I'm thinking it's probably worth paying someone with more experience and resources to do this the right way. I'll want to check headspace for peace of mind anyhow and that's something I can't do without gauges anyhow. Not in a huge rush but hoping it can be done in the next month or two

 

[IronMonster]

If you want to send the whole thing to me I can swap the upper out and check headspace after reassembly. I wouldn't charge anything, just have to pay shipping both ways.

 

[Jcon268]

If you want to send the whole thing to me I can swap the upper out and check headspace after reassembly. I wouldn't charge anything, just have to pay shipping both ways.

That's awesome. Well I haven't got the replacement upper yet. If I haven't freed it up by the time it arrives, I'll strongly consider that offer!

 

[wired]

Are you trying to retain the upper receiver? If not you could just make a cut with a die grinder and split it at the threads with a chisel. Thats what I'd do ( actually I'd pound the barrel out with a wooden or aluminum dowel ) . Last few upper receivers I bought were under $40.

 

[Jcon268]

Are you trying to retain the upper receiver? If not you could just make a cut with a die grinder and split it at the threads with a chisel. Thats what I'd do ( actually I'd pound the barrel out with a wooden or aluminum dowel ) . Last few upper receivers I bought were under $40.

This is about a $150 receiver so trying to keep it looking nice. That's my biggest problem here. I could definitely get that barrel out...but at the risk of messing something up.

 

[Argonaut]

If you want to send the whole thing to me I can swap the upper out and check headspace after reassembly. I wouldn't charge anything, just have to pay shipping both ways.

Ironmonster@ I don't have my reference book.......but you will know. What is the coefficient of linear expansion of the aluminum (receiver) compared to the steel barrel? That will tell if freezing will do any good. I can't remember, freezing it might actually tighten the upper onto the barrel. If not, I would go by Norco supply and have it dipped in some liquid nitrogen.

 

[IronMonster]

Ironmonster@ I don't have my reference book.......but you will know. What is the coefficient of linear expansion of the aluminum (receiver) compared to the steel barrel? That will tell if freezing will do any good. I can't remember, freezing it might actually tighten the upper onto the barrel. If not, I would go by Norco supply and have it dipped in some liquid nitrogen.

Steel is about half what aluminum is but we are not talking about enough material to see much of a variation in a freezer. With the 200+ degree swing with LN2 my guess you would see a couple ten thou separation due to variance in thermal expansion and the aluminum growing more than the steel but I am not smart enough to do the math in my head.

 

[wired]

Some uppers are just so slightly out of spec. This one is the same ID as OD of the barrel and took an arbor to press it in. Same as yours no doubt a wood dowel ( broomstick ) and a BMFH and it will pop out.