I recently bought a TA44R-2 compact ACOG with M16 base which will primarily be used on an A1 upper.  However, I thought I would try it out on my M4 with A3 detacheable carry handle and the ACOG base is too wide for the carry handle channel.  Is this common ACOG knowledge or is my carry handle defective/ out of spec.?  The carry handle is Cardinal Forge if that makes a difference.  I am aware of the various aftermarket mounts; just wanted to try it on the A3 carry handle.

thanks