Crush washer with pinned and welded comp - do I need one?

[danw77 13]

I need to finish the compliance work on my barrel before I bring my lower home and I've run into a problem with the crush washer. The barrel came with a flash hider which I have removed, but I can't get the comp to index properly with the old (already crushed) crush washer. Here's my question: do I even need a crush washer if I'll be pinning and welding the comp? What's the better course of action - leave out the crush washer or order a new one? If I need to order a new one, I'll have to hold off on bringing my lower home (which I planned to do this weekend). I'm getting anxious to shoot this thing and had just about convinced myself I didn't need the crush washer, but figured it best to ask before I drill into the threads on my barrel. Thanks in advance!

[MidwestPX 172]

If your muzzle device needs to be timed, you'll need either shims, a peel washer, or a crush washer. Whoever is doing the compliance work won't want a freely moving muzzle device to drill through.

[mipafox 438]

Use peel washers. You can adjust them to make sure you get proper index. Yes, it can take up to 15 minutes vs. 2 minutes for a crush washer if you are a first timer. But they will solve your problem. Also, they do not cant your comp. If your comp is (someday) silencer compatible, you can't use crush washers because they cant your comp slightly.

[danw77 13]

I'm using the Calvary Comp (http://www.brownells.com/rifle-parts/barrel-parts/compensators/223-cav-comp-sku100000189-1464-5604.aspx) which already has a hole drilled in it for the pin. My plan was to index it, mark the barrel, remove it, and then just dimple the threads enough so that the pin won't let it turn. So I still need some sort of washer? If so, does anyone know of a local shop in the Summit/Livingston area that would have peel washers and/or crush washers? I really should have ordered one when I bought the comp, but it slipped my mind.

[High Exposure 5,664]

Best bet is to get a new washer - either crush, peel, or shims like Ty said.

 

If it is only need a little bit of spin you can grind the base of the muzzle device so it can finish the revolution. Just go slow and make sure you don't grind it down so much that you miss your index or are under 16" on the barrel.

[danw77 13]

OK, thanks for the advice. I only need to get it to go another 1/8 turn so maybe grinding it is the way to go.

[High Exposure 5,664]

Hammer Pair - slow internet...

[danw77 13]

Just thought I'd let you all know that I managed to get it on last night. Pinned, welded, and NJ legal. Did all of the compliance work myself. It was a budget build otherwise I never would have had the confidence to take a drill and grinder to it, but I must say I'm happy with the way it turned out. Probably the best $450 I've ever spent. 

[remixer 1,645]

Crush washers are the easiest way to get it done