AR-15 flash suppressor tightenin

[Dan Forrester]

I picked up a matching LMT upper for my lower I purchased a couple months back and have a question about the flash suppressor. Before I fire any new gun I like to take it completely apart and clean before firing. Part of this disassembly is removing the flash suppressor which was properly aligned with the vents point up to counter act the muzzle clime. It was thought to get off with a crescent wrench due to the crush washer (I believe that’s the what they call them). Now I can’t get it back on the muzzle tight enough for it to realign.

What do I need to do?

Thanks, Dan

 

[blackhawk2000]

New crush washer maybe? Use a real wrench made to fit the FH properly, you'll be able to torque it down better. Crescent wrenches are garbage.

 

[W.E.G.]

How are you securing the barrel while you are wrenching?

 

[Dan Forrester]

That’s the problem, securing the barrel. How is one supposed to do this?

Also what’s the proper wrench?

Thanks for the responses guys.

Dan

 

[Telperion]

Ideally, you want to put the barrel in a vise, use a GI M16 combo wrench or similar tool, and torque the flash suppressor to 15-20 ft-lbs. Don't overtighten, or you can end up constricting the bore.

 

[SigfanUSAF]

Any quality 3/4" wrench will work. Oh, and buy a new crush washer, they aren't designed to be reused.

 

[Dan Forrester]

Any links on where to pick up the barrel vise and fresh crush washers. Are there any other washer options available? Is that armorer’s (I know that’s spelt wrong) wrench considered the correct wrench?

Thanks, Dan

 

[DMK]

You don't need a barrel vice. It's only 15 ft lbs. Get two pieces of soft pine, clamp the barrel between them in a regular vice. Tighten it just enough that it won't turn, don't go trying to crush it.

You can get the crush washers from anyone who sells AR parts:

www.adcofirearms.com
www.brownells.com
www.midwayusa.com
www.rbprecision.com

Are there any other washer options available?

Yes, Peel Washers. You don't want them. They are a big PITA.

 

[DougW]

Put the barrel in the vice, not the front sight! Use soft pine as DMK said, and crank away. I have removed and installed 5 or 6 FH's, and sometimes you have to crank down on the vice. I have a 4" MAC Tool vice that I use.

 

[sigman4rt]

According to AMU (Army Marksmanship Unit) specs, do not torque the flash hider. Get yourself some red Loctite and leave off the crush washer. Hand tighten the FH until properly timed, then allow to "set up" overnight. Torquing the FH onto the barrel stretches the barrel threads and screws up your barrel harmonics.

 

[blackhawk2000]

A crescent wrench is junk because they can easily back off, and round off whatever you are working on.