a good friend just loaned me his compensator so I can get some measurements,just looking I'd say that the actual compensation factor of the thing is almost nil,(haven't shot one installed),the vents are at 90 Deg's to the bore.Might be better to call it a flash suppressor.A true compensator should be venting gases upward and backward. I'm thinking about 6" long total,part of this will be lost to the barrel clamp area with say .050 to .060 holes on the upper half, 25 -30 degrees left and right of top dead center in a pattern of 3/16" .Then Birchwood Casety's "cold blue kit" and Viola! A new true compensator is born.Course will take some time to make.