might be a bit of a silly question but, i have a leupold VX-III on the underside of the 30mm tube, where the front ring would sit, there is a hole/depression. about 2mm wide and 1mm deep. it is offset to about the 7 o'clock position.
only thing i can think of is for a scope ring to clip into to help stop the scope slipping back from recoil. think is i cant find a scope ring with a lug in it to fit.
whats the hole for please