Well, not quite what I thought I ordered...

[jdgabbard]

Ok, guys... Ordered a crush washer for the Retro A1 build I'm doing. Only problem, I should have actually looked at the picture before ordering. The link below is what came in the mail. Still usable???

http://www.e-sarcoinc.com/ar15m16flashhiderwasher.aspx

[nhrifle]

I got that with the A1 parts kit I built into a shooter too. When installed, just leaves you shaking your head asking, "Why?" Just screw the flash hider onto the barrel, go shooting, and be happy.

[jdgabbard]

Did you torque it down with the crush washer??

[I'll Make Mine]

That's a split ring lock washer, not anything I'd call a crush washer. It works by biting into the surfaces as they're tightened, so they have to shave off a little metal to unscrew (I handle small lock washers every day at work). As I understand it, a crush washer works by deforming in a controlled way to allow compressing a joint by a desired amount without exceeding force limits (shear strength of threads, length of available wrench).

[jdgabbard]

This particular one doesn't do that. It's more of a spring. And regains its original shape after taking the flash suppressor off. And I can literally flatten it out with the suppressor by hand.

[MtGun44]

The point of a crush washer is to let you index the A2 style of compensator (this is what the military
calls it) so that the open ports are up and the closed area is down, to prevent dust and stuff being blown
around when firing prone, and to dampen muzzle rise. The compensator is very snub crushing the
washer and will stay where you put it.

Seems like there is no need for one on an A1 style which has no closed ports, and that the spring type
should work on a A2 style, but is not standard.

Bill

[Blanket]

If you are building a correct A1 it will be a high collar lock washer, not a crush or peel washer Russ

[jdgabbard]

So this is the correct profile. Do you still torque them to 15-20 ft/lbs???

[DCM]

Yes it is correct for the A1.
I would put some blue 242 loctite on the threads if it crushes that easy though.