I found this information on Page 68 of the SH4 Manual.
The meaning of the reticle marks is outlined in the table below:
Optic Used-------------(Zoom Level)----------Small Marks-------------Large Marks
Periscope------------(Low Magnification)-----------1°---------------------4°
Periscope------------(High Magnification)-------0.25°(0°15’)---------------1°
TBT-----------------------(7x)-----------------0.2° (0°12’)---------------1°
Hope this means more to you than it did to me
