I have used M21, s SASS M110, SR25, Issued guns. I Own FAL DSA, AR DPMS 308, 260, and 7mm08, My favorite rifle of all is My Scar17. My fal is 1 MOA -1.5. My others are all sub MOA, My Scar is Sub MOA, to this day I have never had an issue with my Scar, not even a last round not locking back on...