Aside from the obvious politics and other strong opinions regarding SIG 516’s, I would really like to know the difference (if any) between the operating systems of the H&K MR223/556 and the SIG 516…I understand that theory and execution are entirely different, so i would be interested in the fundemental objectives that both rifles and thier respective designers were trying to attain with thier original operating concepts.
any and all info would be great