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PS90 - muzzle device / receiver clearance

717 Views 7 Replies 4 Participants Last post by  Jonnyrngo
I could have sworn I saw a post from STL a long time ago where he mentioned a certain range for the proper clearance between the muzzle device and receiver in order to allow proper function (for the delayed blowback/recoiling and movement of the barrel).

I measured my stock PS90 to be 0.015" and now with the CMMG 10.4", it's 0.0095" It still rotates and moves freely, but I thought there was a recommended spec. Has anyone come across this as well?
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Is anyone using rocksett on the adapter or CMMG muzzle device? I seem to think torquing it to 30-33 ft lbs would be enough. On the front end there is no way an adapter or CMMG MD is going to rotate off. If I'm not mistaken the front of the receiver mates with the flats on either device which stops it from turning. On the chamber end of the barrel there shouldn't be any twisting force to unscrew it.

Now I could see using a little rocksett on a MD that is attached to an adapter but not the adapter itself.
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