Got this bad mama jamma today! Awesome machine work just like the Hellfire brake that I have also. Like I said, this brake is replacing the APA "Little Bastard" brake. I will report recoil difference. I need to retake the pictures, only this one worked. Can't really see the brake, sorry
Looking at this, it seems very similar in concept to the Hellfire system... call it the big brother of the Hellfire.
In any event, regarding the universal adapter, does it seat against a shoulder on the barrel, or the end of the muzzle? I ask, because it's often impossible on hunter-weight barrels to have enough meat for a decent-sized thread with an appropriate shoulder... but if the universal adapter seats to the end of the muzzle, then as long as the OD of the barrel at the muzzle is big enough for the major diameter of the desired thread, you're GTG.
I have a Little Bastard on my 300 wm right now, so we'll see the difference with the Sidewinder brake. I also have a Hellfire on my 6.5 and the machine work on that thing is very nice.