Timing muzzle device: shaving down back vs peel washers vs crush washers

**Junkie** · 07-02-15, 18:38

I'm assembling an AR47 right now, putting a VG6 Gamma on it. It's a 16" barrel, so no need to pin/weld.

I have crush washers, but no 5/8" peel washers. I don't particularly like the look of crush washers. Is there any downside to timing it by sanding the back (on very fine paper) rather than using crush washers? Or I can always pick up a set of peel washers.

What's a reasonable torque value for a 5/8-24 muzzle device on a 7.62x39 barrel? The barrel doesn't have much of a shoulder if it matters.

**GH41** · 07-02-15, 19:24

Let me be the first to ask.... WTF?

**Etho** · 07-02-15, 19:27

I think you would spend quite a bit of time, wasted time I might add, doing something like that. But to answer your question, I guess it would work. Never really pondered this particular situation. Those washers help keep it from loosening though too, so there is that to consider.

**Mike Miller** · 07-02-15, 19:39

I thought it was actually common with 3 gun shooters to cut back on their muzzle brakes, but check Robb Jensen's post here

https://www.m4carbine.net/showthread...145#post313145

**Junkie** · 07-02-15, 20:04

I wonder why he considers it a hack job to remove material from the muzzle device.

I could chuck it up in the mini lathe (I think) and try to remove a little metal, or pay someone who knows what they're doing. I don't understand why removing from one side is hackjob and from the other is right.

**BufordTJustice** · 07-02-15, 20:08

My concern: lack of maintaining a perpendicular surface on the rear of the muzzle device. There is enough play in the threads to allow a baffle strike in a muzzle brake due to it being torqued against a non square surface (whether the rear of the device or the barrel shoulder).

Same reason that precision muzzle devices earn against using crush washers. The AAC shim set is cheap and functional. Gitchusum.

**Junkie** · 07-02-15, 20:36

It's a VG6 Gamma, not particularly long. I won't be mounting anything else to it either. I could certainly chuck it up in the lathe, throw a runout gauge on to make sure it's really square, then spin it and hit it with a flap disc or something. I'd make sure it was square after, too. I don't think trying to cut it with anything else would work too well as it's nitrided. I'd also consider taking off some of the shoulder on it, as the barrel's shoulder is significantly smaller (there's not much: http://www.blackriflearms.com/16-762...rel_p_168.html ).

I guess I'll probably just pick up a shim kit, I just think it's prettier with nothing there.

**BufordTJustice** · 07-02-15, 20:46

Originally Posted by Junkie

It's a VG6 Gamma, not particularly long. I won't be mounting anything else to it either. I could certainly chuck it up in the lathe, throw a runout gauge on to make sure it's really square, then spin it and hit it with a flap disc or something. I'd make sure it was square after, too. I don't think trying to cut it with anything else would work too well as it's nitrided. I'd also consider taking off some of the shoulder on it, as the barrel's shoulder is significantly smaller (there's not much: http://www.blackriflearms.com/16-762...rel_p_168.html ).

I guess I'll probably just pick up a shim kit, I just think it's prettier with nothing there.

Well, seeing that you know your way around a lathe, that would work just fine. Just a lot of work, as you stated.

I think the AAC shim kit is around $12.

**MegademiC** · 07-02-15, 21:47

Also, which I haven't seen mentioned... removing material exposes bare steel to the environment. Why would you not use washers? Correct timing, and coated device with minimal effort/cost. You may be able to do it yourself, but time is money. I can make my own soap. But I dont.