SIG SAUER SWISS ARMS SG552 - Manual (Page 15)

3.9. Gas valve position
With the SG 552, the gas volume required for the func-
tion of the weapon can be controlled by the gas valve.
Position I
(Rib of gas valve in vertical position (illu. 31)).
Under normal conditions, firing is effected in this
position.
Position II
(Rib of gas valve in slanting position (illu. 32)).
When cycling or ejection problems are encountered due
to heavy fouling or icing-up, the gas valve is to be turned
clockwise as far as the stop. In this position, a larger gas
quantity acts on the gas piston.
The adjustment of the gas valve is effected manually, and,
in case of a hot or heavily fouled weapon, by means of a
cartridge or auxiliary aid.
Firing with gas valve in position II is an exception. As
soon as the weapon works, the gas valve must be turned
back to position I, otherwise the recoil is intensified and
the weapon is unnecessarily
stressed.
29
Handling
3.8. Aiming, firing and adjusting with flip up sight
To aim, align the eye, flip up rear sight, front sight and target.
At all ranges, the fore sight should be aimed at the center
of the target. Firing is therefore to the point of aim (illu. 29).
Adjusting
To correct the elevation, release the flat head screw of the
flip up sight and shift the sight plate up or down respecti-
vely, then lock the flat head screw.
Front sight (illu. 29) Rear sight (illu. 30)
1) Front sight 1) Rear sight holder
2) Front sight, lower part 2) Rear sight
3) Front sight screw 3) Flat head screw
4) Front sight disc
Elevation
High shots are corrected to shift the sight plate down.
Low shots are corrected to shift the sight plate up.
Windage
Shots to the right are corrected by turning the front sight
screw to the right.
Shots to the left are corrected by turning the front sight
screw to the left.
SG 552 with flip up sight
(average point of impact correction per one mark
in the height and per one turn in the front sight screw)
Firing- Height Side
range
100 m
2,2 cm/0.87 inches 2,4 cm/0.94 inches
200 m 4,4 cm/1.73 inches 4,8 cm/1.89 inches
300 m 6,6 cm/2.60 inches 7,2 cm/2.83 inches
Handling
28
illu. 29) Front sight illu. 30) Rear sight
illu. 31)
Gas valve in position I illu. 32)
Gas valve in position II
1
2
3
4
1
2
3