Look up Black River Tactical. They sell what is known as a lineage compensator. I have one on my DPMS lr308. The exhaust port holes are positioned facing forward. This directs the muzzle blast away from the shooter as well as others on the line. Additionally I feel this pushes the weapon directly back, reducing muzzle rise and felt recoil.
It may not be for everyone but my thoughts are it softens the blow thus allowing for a better sight picture and resembles an a2 flash hider. The guy I dealt with there several years ago was Clint,$60 plus dollars at that time.
Hope this helps,