the on off tab deals with the mag. They where designed to allow a full loaded mag to no tallow rounds to feed from the mag dependent on the position of the switch. This was an ammo saving thing mad up by higher ups. You could load the mag then chamber a round and loading it like a single shot unless you needed to fire faster.
Fantastic rifles by the way. They can get shoot at some impressive ranges.
hello..do you speak of the blown up pic from my original post? if so i copied word for word any # off the rifle too help me in my search today...please let me know and maybe u have the needed info for age,value and firing condition if wanted to try her out...thx ***be looking for your response 303 tom***