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truevil1313 08-14-2008 04:23 AM

build up behind flash hider?
Ok, I removed my A2 style flash hider today in order to install a new one from LaRue Tactical. When I removed the old one, I found a lot of build up on the barrel end. Is this normal? Was I correct to scrape all of this off before I installed the new one, and what causes this? Was the first one not installed correctly? Just a few questions I wanted to throw out there.

JWIII 08-14-2008 06:06 AM

Not meaning to hi-jack, but I have question also...

I was looking at getting a diff. muzzle break, does a gunsmith have to install it? If so; why?

truevil1313 08-14-2008 11:59 AM

No, not if your barrel is threaded. It is a simple matter of unthreading the old one and threading on the new one. But , like my new one, I had to use a peel washer and slice off quite a bit of it, in order to get the new comp. to line up correctly.

G21.45 08-14-2008 12:24 PM

:) Yes, the crud is normal. Next time before you start scraping, let the end of the barrel soak overnight in something like automatic transmission fluid or Kano Kroil, and follow-up with engine degreaser and a brush afterwards.

If you want to remove an older flash hider, first determine whether it screwed on with a standard left-hand off thread, or a post ban model which may be pinned, soldered, or press fit in place. (If this is the case, I'd let an armorer remove it.)

If it's threaded on you're going to need a strong vice, vice blocks, and a 3/4" armorer's wrench. (Brownell's or Bushmaster has these items.) There should be some sort of compression (crush) washer behind the flash hider; and, you'll need to install another one on the new installation. These things are usually torqued back on with no more than 20# force.

Since you're going to all this trouble, be sure to get a flash hider that doesn't have an open port on the bottom - That's a real nuisance when you're firing prone.

robocop10mm 08-14-2008 12:43 PM

The A-2 Flash Hider is indexed to point in the proper direction. You use a peel washer to get the index correct. The A-1's used a crush washer and were screwed down tight. Using the peel washer there is almost always a small gap between the muzzle and the FH. That gap will collect carbon. Remove as much as practicable before installing a new FH or Brake to insure a good solid fit.

G21.45 08-14-2008 12:56 PM

According to the gunsmith I used to work with, you can use either a crush or peel (split) type washer. It's just a little easier to final fit with the split type.

(And, a little tighter if you use the crush.) ;)

JWIII 08-14-2008 06:28 PM

Thanks for the info... Again sorry, I didn't mean to hi-jack your thread. Just seemed a waste to start a new one.

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