I recently bought a MSAR Stg-556 gen4 at a gun show and need some help. First off, if anybody has any experience with this rifle please share. Any tips/tricks or advice would be greatly appreciated. I also bought a MeproLight M21M today and mounted it. The optic in the pics came with it, it's a cheap BSA RD30. The problem with the MeproLight is its too high when using a proper cheek weld. I read the 1913 mount is calibrated for the optic at the factory, so I'm guessing I shouldn't remove it. How can I lower it? I really like the optic, but if need be I'll put it on a flap top AR. What optic would you recommend for a MSAR? Thanks for the help.