I have 2 HS403G models both on Vz 58's in 7.62x39. Several thousands of rounds through both and no issues. I use locktite and torque to the max. limits of each machine screw. Maybe I am lucky? I am not willing to pay $750 for an aimpoint micro but I am willing to compromise on a good product for the price. As with all inexpensive good optics inability to handle high recoil loads seems to be the compromise. I have destroyed 2, trs 25's on shotguns. Again only my own personal obervation, they don't last with high recoil loads. In my use the only inexpensive optic that has survived high recoil loads is a Vortex Strikefire. Shotguns, M14's all good to go.