My gunsmith installed a crush washer behind my new AAC Blackout flash hider attached to a Colt 6920. I read the AAC package when I got home and it said, “DO NOT use a washer…” Does anyone know of any potential problems I could run into with it installed this way? I will never use a can due to living in CA, so that shouldn’t factor into any potential problems. Thanks
You may have better luck asking in the NFA forum where suppressors are cussed and discussed.
Scoby
No problems, to my knowledge, if you’re not using a suppressor.
Your not supposed to use a crush washer behind the blackout as the directions state due to alignment issues with the can. No can, no problem. At least it will be easy to take off, unlike using the rocksett method where you have to soak in water overnight to get the danged thing off.
Could you explain the ‘rockset’ method? I just hand tightened mine.
Also, is the blackout supposed to slide over the barrel a bit? I have the suppressor mount style, and there’s that gap inside before the threads, and it just looks like the barrel is supposed to go inside the FH a little… but I guess that doesn’t make sense as you’d have to get the tip of the barrel circumsized.
I figured a hijack wouldn’t be a bad thing since your question was answered. If OP is looking for more info, let me know and I’ll remove this and start a new thread.
Rockset is just a liquid thread locker. Used for the AAC QD Suppressor Blackouts.
No problem as long as no can is used.
C4
Based on the lengths described on AAC’s website (specifically their overall added lenghts), yes, the suppressor mount version is supposed to go over the barrel a little.
-B
Rocksett is a ceramic based threadlocker, much like locktite, but with a lot higher temperature rating. You are supposed to clean the threads on the end of the barrel and on the inside of the flash suppressor with a degreaser (brake cleaner). Apply some small beads of the rocksett on the barrel threads and snug up the flash suppressor and let it set for 24 hours before use.
There is an excellent video on youtube (search for m4-100) that shows mag dumps with can attached and the mount comes loose and the user gets a couple baffle/end strikes and ruins the can. That shows the importance of having your flash hider mount securely fastening when using a QD type can.
Thank you guys for answering my question. I appreciate it.