>>64117881
>the one on the original SCARs were breaking optics
What broke optics (and lasers/lights) was an oddball forward impulse when the bolt slammed home, sort of like airguns with a piston.
The Eotechs for example had the batteries in line with the barrel, which meant that recoil shook the batteries back and forth with enough violence to fuck up the contacts. The EXPS models have the battery perpendicular to the barrel for that reason. It wasn't the the charging handle that was physically impacting optics, but the vibrations transmitted into the optics and electronics. The most recent SCAR models also have a connection of the bottom of the upper to give it less of a "tuning fork" structure but I don't know how big of a deal that is.
One thing that happened with optics mounts was knobs or levers interfering with the charging handle during a pull. That doesn't break the optic, but it's a source of annoyance. Before NRCH there were aftermarket charging handles that had a downward curve just to give enough clearance for the hand to drag against the side of the receiver without bumping into the protrusions.