Closeup view of cam on scope
A detail view of the ballistic cam, when turned to adjust range the cam would ride on the "pin" at the tail of the mount & raise/lower the rear of the scope which was attached in front w/a pin & was spring loaded to the mount. The early scopes were standard commercial Redfields which were modified by the Army w/the M118 ballistic cam attached to the original adjuster & had the reticle modified w/stadia lines added to estimate range thru the lens.
Other Sizes: Original