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Gunsmithing lmt barrel hard to install causing issues

Tonsofguns

Private
Full Member
Minuteman
Feb 24, 2017
817
256
Northern Va
Picked up an LMT mws on a trade.

Received it with a muzzle brake untimed, and an extra muzzle to replace that one.

I have tried everything I could, including heating the muzzle, putting a metal rod through the brake for leverage (RIP brake) to remove it, and I cannot get it off.

Also, barrels are extremely hard to install, and the only way I can get the barrel in the receiver all the way, is by hammering down on the top of the muzzle (which could be the reason why the muzzle won't budge).

I have one other mws and two mrp, and ive never had this issue before. You can easily get the barrel in and out with hand strength, and not even too much pushing.

I've tried with different barrels on this mlok receiver, and they all have the same issue. Is this receiver out of spec? Also could hammering the barrel from the top cause the threads to bend, making it impossible to remove? Is this any other way to remove this muzzle?
 
If all you have for a tool is a hammer everything looks like a nail.

You should not need that much force to slip the barrel in and you know this because you have other LMTs.

Send the gun in to LMT and have Gene look at it.

I had an issue with mine, completely owner error yet LMT was going to eat all the costs. I insisted on paying for my stupidity but was really impressed with their service.
 
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Are you putting the barrel in a barrel vise or using a reaction rod before working on the muzzle device? If your putting that much force on trying to remove the muzzle device and that force is being transferred into the upper receiver, something bad could have happened at one point. Maybe even on the install of the muzzle device originally.

Yes hammering on the muzzle device if its not tight against the shoulder will mess up the threads.

My guess it's way over torqued with red locktite or something. Heat should loosen it, but it has to get to 600 or so degrees for the red to turn back to liquid. Proper tools would be my first try if you aren't using them already. Or send it to LMT, or back to the seller for a refund.
 
Put the barrel in the freezer for a few hours. Take. A heat gun or blow dryer and he up the receiver threads until you can’t touch them no more.

place frozen barrel in a vice while the blow dryer is still going. Once you get it set grab the upper and slip it in the barrel. You have to be fast while doing it or it won’t work.

I just out together an ADM upper that I had to do this too. The barrel would only slip in just a little bit but once I did the listed above it went together easy.

also get a reaction rod if you do not have one. I bought the cheap one from Botach.
 
Put the barrel in the freezer for a few hours. Take. A heat gun or blow dryer and he up the receiver threads until you can’t touch them no more.

place frozen barrel in a vice while the blow dryer is still going. Once you get it set grab the upper and slip it in the barrel. You have to be fast while doing it or it won’t work.

I just out together an ADM upper that I had to do this too. The barrel would only slip in just a little bit but once I did the listed above it went together easy.

also get a reaction rod if you do not have one. I bought the cheap one from Botach.


LMT MRP/MWS system is unlike a stoner design AR.
 
Did the screws that secure the upper to the barrel collar backout easy or does it feel like there was resistance that might indicate the upper "pinch" area was tweaked?

Do the screws fit back into the upper without interference?
 
Reaction rod is the wrong tool to R&R a muzzle device. You need a barrel vise as close to the MD as possible. I am assuming it is NOT a barrel shorter than 16" and pinned and welded. How did you remove the barrel from the receiver? I assume you had to beat it out. Does the new barrel slip into your other MWS receiver?
 
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tried different barrels, they won't fit. Something is off with the receiver.

In any case, i found out what most likely happened. i spoke to the guy i got it from, and he was torquing the muzzle brake with the receiver on. I can actually see the marks on the receiver.
This must have thrown the receiver out of spec.

At this point, I cannot for the life of me get the barrel out now, and still cant get the muzzle off the other barrel.

The good news is a spoke to Gene at LMT, and he said our fault or not, he'll replace it if it can't be fixed. He also said he'd take the muzzle brake off the other barrel. Problem solved. These guys are top notch, and so is the quality of their products.

Hence why i own 2 mrps and 2 mws. thanks for the help guys. Some good tips for the future.
 
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