I've never heard of any expectation that the wrench flats would 'clock' to a specific alignment. If the muzzle device requires specific orientation (clocking) to align exhaust ports, shims are available from most suppressor manufacturers(or ebay). A crush washer can be used but requires significant torque to 'crush' in most cases. A solid, non-marring barrel clamp will be required. I use a piece of split automotive heater hose and a 4-5" bench vise. Be advised: a thin profile thread protector will not withstand that sort of torque w/o splitting or stripping threads. Knurled thread protectors are available that don't use wrench flats.
Hope this helps.
