Help!! My A2 flash hider won't set properly....

[Grendel-Gene]

I got a Liberty 18 inch Grendel barrel and I got an Alexander Arms A2 flash hider... So far, so good.

But when I install the flash hider and torque it down reasonably ( not sure of the precise amount of FT / Lbs, but I am a mechanic... ), the bottom of the flash hider comes to rest between the 7 and 8 o'clock position.... and not the 6 o'clock (as it should).

So.....

Do I need some more or some different washers? I only have what came with the flash hider from Alexander Arms.....

By the was, this is yet another reason for me to dislike the A2s... and love the A1s!!!!

Thanks.

[sgt_murf]

do you have crush washer? ( slight Convex shaped aka dome shape and not split)
If so back the Hider off re index and reapply until the correct alignment is done. BTW what torque value are you going for?
If all else fails drive North to Arkansas I'll help ya brother

look here
http://www.brownells.com/.aspx/lid=10367...sh_Hiders_

[Grendel-Gene]

I do have the crush washer.... it was supplied with the A2.... it doesn't get me where i need to be!!!!

[LRRPF52]

After locking your barrel in clamps in your vice (not the upper, but barrel), you can do at least one of two things.

1) Use Peel washers to index properly.

2) Remove some material from the face or back of the crush washer.

[leopard6.5]

Grendel-Gene: The last A2 flash hider I put on was about a month and a half ago on a Satern Spartan barrel from AA.

I used a lot more torgue than I thought I would need to, to finally get it to start crushing and allow me to go around enough to align it right.

Once I got it to start crushing the washer it seemed easier to turn but I thought I was going to twist the barrel by the amount of force I was using.
I made sure I had it clamped in my vise with the proper clamp securely before I finally applied enough force to get the crush washer to finally start crushing.

Before that I could only get the bottom of the flash hider to the 3 o'clock position as I was looking from the end of the barrel toward the receiver.

I also had no way to test how much torque I was applying but it sure felt like a lot.

Hopefully this helps you and good luck.

Lee

[Mutt]

Use a peel washer ..... it lets you time correctly and you don't have to use excessive torque.


Better yet ..... toss the flash hider and put a WCI brake on that thing.

[Grendel-Gene]

Ok, maybe its me.....

So i am suppossed to "force" the flash hider onto this crush washer which will then collapse as i approach the right timing position.... is that correct???

[leopard6.5]

Grendel- Gene: In short, Correct.

The crush washer( at least mine did) actually collapses to a thinner size as you tighten it down and you stop when it is timed correctly.
It then almost acts like a lock-washer to keep tension between the flash hider and barrel so the flash hider doesn't loosen up and fall off.

The actual point where the crush washer finally started to crush thinner is where it was really hard to tighten for me and it actually felt just a little easier to tighten after I hit that point.
Aren't you glad I gave my short answer first.

Good Luck.

Lee

[leopard6.5]

Grendel-Gene: I don't know if AA has changed suppliers or not for their crush washers, you'd have to ask them, but this last one I did seemed to take more torque to start the crush than the ones I had done previously.
That's why it kind of scared me that I might do damage to the expensive barrel. Fortunately it all worked out fine.

Of course maybe my arms aren't as well calibrated as they once were.

Lee

[sgt_murf]

PM sent

[Grendel-Gene]

Ok then... i guess the clue is in the words "crush washer".... DUH!!!!

I just dont like forcing things... especially on expensive barrels.

I naively thought that perhaps the threads were cut to time correctly when the flash hider was at the proper torque.... and the washer was just a washer...

But i think i have it from here. Will put the barrel on the vice tonight and play with it. Thanks for the advice and help.

[texasgrunt]

Not to completely hijack your thread, but how do you set a barrel in a vice as opposed to the upper? It makes sense why you would do this (to avoid warping the upper when torquing, I suppose), but I'm not clear on how to vise the barrell tight enough to torque without scarring the barrel.

I know, newbie shining through...

[leopard6.5]

texasgrunt, the completely correct way is to buy a barrel clamp that goes around the barrel to protect it and then gets clamped in a bench vise.

I don't remember where I got mine but I'm sure several companies( midwayusa.com, etc.) carry them.
I've also heard people talk about using other things( pieces of wood, pieces of starboard,etc.) to use between the bench vise and the barrel and they may work okay if you are careful.
I just never wanted to try it with a $500.00- $600.00 dollar barrel.

Lee

[stokesrj]

Brownells carries barrel clamps, and rosin to increase the grip on the barrel which will prevent the scaring you are concerned with.
http://www.brownells.com/.aspx/pid=12470...-VISE-JAWS
http://www.brownells.com/.aspx/pid=1123/...duct/ROSIN
Bob

[sgt_murf]

Block of wood with the correct fixture works like a champ but ya will need Rosin to get a grip on the barrel the type I am mentioning is the EXACT type used for a bolt gun like the Remmy or Savage and bolt to your bench.
I have on my bench the Alum type that the Gov't armourers use that go in a vise with two differant profiles A1 and A2 and up. these will work though I suspect that wood inserts used the other mentioned types are probably better suited to differant profiles.

Look in brownells or midway for barrel clamps to get a visual of which types I (and Leopard) are referring to.
http://www.brownells.com/.aspx/pid=17199...ARREL-VISE <<< shows Alum jamws Wheeler engineering uses wood blocks (oak if I real correctly) made to the same type fixture
http://www.brownells.com/.aspx/pid=12470...-VISE-JAWS <<<< type I have on the bench ... actually I have both type available for when I am doing anything with my own weapons.

agggh stokesjr ya beat me to it

[sgt_murf]

Here is another type
http://www.brownells.com/.aspx/sid=36179...00_d_11483
or

http://www.midwayusa.com/product/226100/...d-bushings

[LRRPF52]

Not to completely hijack your thread, but how do you set a barrel in a vice as opposed to the upper? It makes sense why you would do this (to avoid warping the upper when torquing, I suppose), but I'm not clear on how to vise the barrell tight enough to torque without scarring the barrel.

I know, newbie shining through...

This is an important question. The reason for clamping the barrel and not the upper is that if you clamp the upper, you will be torquing the barrel and barrel extension, which you don't want to do. The barrel itself must be clamped in the vice very tightly, with insulating blocks. I personally use the resin-type rubbery blocks with magnets that hold them in your vice jaws, and they have channels in them for tubulars and angles as well. You do have to crank down on the vice to get a secure hold of the barrel, or it will slip.

[Bill Alexander]

Crush washers are stainless. The washer is designed to collapse as flash hider is indexed. Always remember to apply an EP grease to the parts before the assembly process. A useful technique is to just bring the unit to index or slightly behind and then undo it. Wipe everything down and then nip the flash hider to position. Toque is specified as 35 ftlbs at installation but this is near impossible to measure correctly or to achieve. The peel washers were replaced not becuase they did not work well but because the phenolic resin used to laminate them would on occasion break down from heat and cleaning chemicals.

Those who ask about the thread size and why we use 9/16-24 should examine the shoulder required to provide a support for the crush washer. The correct specification for a 0.750" diameter gas block barrel is to run out at nominally 0.725" and then step to 0.700 for a length of 0.750 behind the muzzle device.

[Grendel-Gene]

What does the "EP" in EP grease stand for ? ( I want to be sure I use the right kind ).... Thanks.

[leopard6.5]

Grendel-Gene: The EP stands for extreme pressure( as opposed to extreme temperature which a lot of greases are) and the tube of grease should say EP on it somewhere( at least that's what mine says).
It comes in both regular and synthetic grease.
Sorry I forgot to mention that earlier when I was talking about the torqueing.

Thanks Bill A. for clarifying the procedure.

Lee