No washers are required with the cyclone since it does not need to be clocked. It only needs a minimum shoulder of about 2mm over the thread to square up on. One of the things that worried me about the prototype Gimp tested was the fact that the FH could be installed on the piss by improper use of the crush washer.
The two port brakes are supplied with a shim kit for alignment or you can get a smith to turn down the face for a no shim fit. One customer using the brake with the shim kit and suppressor is getting good results from a DTA. Just less than 1 moa shift can on or off and groups around .375".
Current weight of the 6.8 and 556 as designed in titanium is 155 grams x 165mm OAL and 145 x 150mm OAL. You need to also add the weight of the brake which is around 74 grams in 15-5 PH SS. These may change during testing but not much. The 762 can is well tested and for its size is a very efficient suppressor which provides the same sound reduction as the thread on 762-20. Using M193 556 Belmont in the 762 can with a Colt Commando 11.5" barrel provided 138 dBA average at the muzzle but with a bit more back pressure than a dedicated 556 suppressor. This was tested with the standard front site gas block, not an adjustable.
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