Hey guy's I want to install this new Griffin Armament M4sd2 on my Mod 1, but don't want to screw anything up. All advice is welcome. Is the Flashhider on my Mod 1 pinned or anything? It is factory stock.
- Thread starter Shoottothrill
- Start date
How long is the barrel? If it's 14.5 plus the flashhider, then it's probably pinned - look on the bottom of the flashhider for evidence of a tig-welded pin. If it's 16, hold it down on the bench with one hand and unscrew the flashhider with a wrench in the other. 
I had to clamp my upper in my vise blocks to get the flash hider off. Mine was on tight I could not hold on to it with one hand and turn the wrench with the outer.
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vipers28
Guest
Have fun bud. My mod 1 A2 FH was something else to get off. I used a propane torch, upper receiver block in a vice, a rubber vice to grasp what little barrel was showing and a open end with a cheater bar... That SOB was smoked on there!!!
On my LMT, I put a wooden block (cut to size from a 2 X 4) in a vise, sticking up; put it in the mag well. Put a wrench of appropriate size on the flash hider and strike opposite end of wrench sharply with a hammer. I'm not advocating this, but it worked for me. YMMV...
This is exactly what you need... does anybody make one like it (without the KAC price?).
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vipers28
Guest
The problem is with KAC E3 you can't use others like GG&G or Geiselle. They won't fit like the KAC one does. $56 vs $86. Plus you can use this on SR15's and SR25's.
If it is rockset on there(most likely is) soak it in water overnight, that breaks down the rockset. Rockset doesnt break down from heat so torching it wont do anything. Rockset needs a shock to break it loose otherwise that is why judgedelta's "smack the wrench with a hammer" method works.
I see a professional gunsmith in my future. Doing this myself to a 2,000.00 AR is making me nervous.
rockset will withstand around 1500 degrees before it breaks down, that's why it's used and not blue or red loctite. it only has the holding power of something like blue loctite but has much greater heat resistance. I would NOT want to heat a flash hider hot enough to get rockset to break down. just soak it in water overnight.
If it is rockset on, throw the barrel in a vise and hit the flash hider square on with a hammer. My SR-25 flash hider was near impossible to get off, the hammer works.
The mod 1 I installed a brake on just had a crush washer, and wasn't all that hard to get off.
The mod 1 I installed a brake on just had a crush washer, and wasn't all that hard to get off.
Whatever you do, DO NOT use the receiver (upper or lower) as the holding point when removing or installing a flash hider or brake. Some of y'all (^) were lucky you didn't break anything.
Use a barrel vise, a wrench on the barrel attachment, and whack the wrench sharply with a big hammer. Instead of a barrel vise, I actually use two blocks of hardwood and a bench vise, then tighten until the barrel doesn't turn when the wrench is hit.
There are too many cases of destroyed receivers or barrel extensions twisting off.
Use a barrel vise, a wrench on the barrel attachment, and whack the wrench sharply with a big hammer. Instead of a barrel vise, I actually use two blocks of hardwood and a bench vise, then tighten until the barrel doesn't turn when the wrench is hit.
There are too many cases of destroyed receivers or barrel extensions twisting off.
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vipers28
Guest
No Rockset on them. Crush washer. I just took mine off my 14.5" in 10 seconds. I used the KAC tool, vise and a wrench, piece of cake.
No Rockset was used on my MOD1 flash hider but be careful. When I took mine off somehow my rail came loose..... I ended up having to buy a barrel wrench to tighten things back up.
Just a heads up. I'd never seen a URX come loose but mine did.
Just a heads up. I'd never seen a URX come loose but mine did.
