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Posted: 4/16/2009 8:15:11 PM EDT
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I am swapping out the A2 FH for a YHM Pantom on my new BCM M4. Try as I might and using new crush washer, the FH is about 3/4 of a full turn off from being "clocked" correctly.
What am I doing wrong? Am I putting in the crush washer upside down? Please forgive my ignorence and help if you could. Thanks 
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| You may need to try more than one crush washer, even if that means trying the old one. Yes. They still work fine after removal. If that doesnt fix it for ya, you may need to try the jam nut like what Smith Enterprizes sells with their 1002 model muzzle brake. I dont know if they sell it seperate, but it may be worth an E-mail to find out. If your not familiar, it's basicaly a jam nut .200 thick with flats for a 3/4" wrench. I have used this method when all else fails and it looks great. The washer is park'd like the YH FH, so it should match just fine. As for direction the crush washer faces, it's concave side otwards the brake/FH. |
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The build section were in now states 15-20 lbs. and that sounds about right. I have gone as high as 30 lbs. You may even need to snug/ loosen, snug/ loosen a few times to get it right. Others may feel you need to throw out a crush washer if used once, but they have stayed put for me after several uses. It's not that I reccomend their re-use if you have others to try, but it will work just fine if thats all you have on hand. FH's and comps. dont really need to be too tight. A last resort for me would be to sand down the tapered face of a used crush washer on a flat surface with wet/dry fine grit paper. Go slow and re-try as needed. By sanding on the tapered side of the washer, it hides any bright surface caused by the removal of the parkerizing. Use some light lube on the threads as well while tighteneing the FH. A light touch of oil is all you need, and that will burn off with the first few mags of ammo.
EDIT: Too late eh? Congrats! 
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Kennywiz
I have the same problem( same flash hidder ) and I'm one half turn from the flash hider being properly clocked. When you say you powered thru it you mean you continued to apply torque and while doing so the crush washer collapsed ? Do you now have correct alignment? Haven't replaced a flash hider before and didn't( wasn't sure how much the crush washer would give / collapse ) want to do any damage to the barrel, thought I'd ask here before screwing things up. MC |
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Quoted:
Kennywiz I have the same problem( same flash hidder ) and I'm one half turn from the flash hider being properly clocked. When you say you powered thru it you mean you continued to apply torque and while doing so the crush washer collapsed ? Do you now have correct alignment? Haven't replaced a flash hider before and didn't( wasn't sure how much the crush washer would give / collapse ) want to do any damage to the barrel, thought I'd ask here before screwing things up. MC Tighten the flash hider down as far as you can, and then back it off. Re-tighten it, and it will twist on there farther than the previous turn. Keep tightening and loosening until the FH is timed correctly. |
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