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1/25/2018 7:38:29 AM
Posted: 3/6/2006 6:16:53 AM EST
I was at the range breaking in my new Adco MK12 Mod 1 upper and the groups suddenly opened up to 5 MOA. I went to clean the bore and noticed the flash hider had come loose. I had tightened it on as best I could and the groups went back down again and the flash hider didn't loosen up again.

What is the proper way to tighten this flash hider on so it doesn't come loose again?
Link Posted: 3/6/2006 7:18:31 AM EST
What type of washer are you using?
Link Posted: 3/6/2006 7:59:11 AM EST
I actually can't tell you. This was a complete MK12 Mod 1 style upper I bought from Adco Firearms.
Link Posted: 3/6/2006 1:26:43 PM EST
What color is the washer. Typ, crush washer = black, peel = sliver, Lockwasher has a angle cut in it.
Link Posted: 3/6/2006 9:03:28 PM EST
It is black.
Link Posted: 3/6/2006 9:44:15 PM EST
[Last Edit: 3/6/2006 9:50:27 PM EST by mm34b]
Torque should be 15 to 20 pound-feet according to the Marine Corps Technical Manual using a peel washer.
Link Posted: 3/7/2006 2:05:04 AM EST
get a new washer, a barrle vise, and adjustable wrench.

You need to clamp the barrle in a vise, using vise blocks or or soft material. remove old washer put new one on tighter the sob up then time the a2 w/ the barrel. If you whish you can also use red loctite, but it is not needed.
Link Posted: 3/9/2006 9:07:41 AM EST
Call ADCO, if they built it, i'm sure they will be happy to fix the problem for you.
Link Posted: 3/10/2006 8:02:53 AM EST
I put a PHANTOM Old School on my 14.5 LMT

it came with a Black Crush Washer!

I like to see someone crush it

Even the Crush washer on the A2 Bird cage wasnt crushed by LMT

Those are very Tuff
Link Posted: 3/11/2006 4:55:38 PM EST
dont use red loctite = PITA if you feel you need loctite use blue. grab a 3/4" wrench and tighten it down.
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