Do the clamp on side mounts loosen while firing or do they stay where you put them?

Thanks,
Ron

They only move if you bump the throw lever. Several models are designed so the lever is locked by pulling down, pushed the last bit fwd, then allowed to move up so the bracket of the optic locks it down against casual bumping.

There are also ways for all (that I have seen)side rail clamps to be set tighter with a central screw. The clamp barely clears the side rail, then the lever throw makes it plenty tight for most.