M1D sniper rifle with M84 scope
is shown above an M1C sniper rifle with M81/M82
scope.
The original rear sight of the M1
would not hold adjustments very well, so a
locking bar was added in late 1942 which could be
tightened after sights were set. This is shown in
the M1C. An improved sight, the T105, was
standardized by the end of WWII, and is shown on
the M1D, above.
Each click of either elevation or
windage changes the strike of the bullet
approximately one inch on the target for every
100 yards of range, over its effective range.
e.g.:
One click will move the bullet strike:
1 inch at 100 yards
2 inches at 200 yards
6 inches at 300 yards
12 inches at 600 yards
Windage can be adjusted 16 clicks
to the right or to the left of center index, and
elevation can be adjusted from 0 to 72
clicks.
Remember, to be able to get
consistent hits, the rear sight must be zeroed
for the various ranges, and the sight setting
recorded, and should be kept in the accessory
compartment of the stock for reference. To move
the mean point of impact up, raise the rear
sight. To move the mean point of impact to the
right, move the sight to the right, and so
on.
The battle sight setting is the
300-yard zero, less two clicks.