So I have been playing with different muzzle brakes over the year for various 10.5" uppers on M16s. For me it is always a battle to keep the muzzle rise to a minimum.   So I last night tried a new brake. It was a UM tactical rage brake. It is adjustable for the amount of downforce you want. I was thinking to put the maximum downforce to start with. My muzzle on a good burst actually went down. I made some adjustments and reduced it and was able to easily hold it from climbing. The only thing I didn't like was there is a pretty big flame out the front and when on a target it covers it up.  It is also pretty damn long on a 10.5" barrel.  Very cool new thing.  Disclaimer- I have no association with them and had to pay for item from a local distributor.

I've had good luck with the AAC 51t compensator mounts.