Manual

Fig. 12. Determination of mean point of

impact (MPI):

1 - by consequent division of lines; 2 - with

symmetrical arrangement of hits. CTn

means MPI

Repeat test-firing to make sure that the above displacement of the

front sight and its body is properly done.

After the sniper rifle has been zeroed, remove the old notch and

make a new notch on the front-sight body.

2.4.4. To zero the rifle with the optical sight attach it to the rifle

and put the cheek plate on the butt. Rotate the knobs to set the sight

angle knob at division 3 and deflection correction knob at 0. Perform

the test firing with the aid of the optical sight, the conditions being

the same as for test firing of the rifle with the aid of the open

sight, but the check point in this case is marked at a height of 14 cm

from the point of aim.

If, as a result of the test-firing, all four hits are arranged in a

circle, 8 cm in diameter, but the mean point of impact deviates from

the check point by more than 3 cm, determine the deviation of the MPI

and introduce the appropriate corrections into the settings of the nuts

on knobs of the sight angles and deflection corrections.

Displacement of the nuts by one division relative to the scales on

the bands of the knobs in firing at 100-m range will change the

position of MPI by 5 cm. To introduce corrections release screws on the

knob ends by 1š1 1/2 turns and while rotating the sight angle nut and

the deflection correction nut, manually, displace them by a necessary

amount and tighten the screws.

After the corrections have been introduced in the knob setting,

repeat the test firing. If, as a result of the repeated test-firing,

all the four hits are arranged in a circle, dia. 8 cm, the MPI has

matched with the check point or deviated from it to either side by no

more than 3 cm, the rifle is considered zeroed.

After zeroing the rifle, record the position of the MPI in the

Service Log.

2.4.5. To detect the range up to the target proceed as follows:

Match the target image with the range-finding scale of the reticle

so that the target base is on the horizontal line of the range-finding

scale, and the target top point touches the upper (dotted) line of the

scale without clearance.

Take off the range-finding scale readings in the point of touching

the target.

A digit which happens to be in the point of touching determines the

distance up to the target (in Fig. 13 the distance up to the target is

400 m).

2.4.6. To deliver firing at night or in twilight turn the micro-

tumbler lever to the position "BKJi" (ON).