Summary Description
Semi-Automatic Sporting Rifle SIG-AMT
cal 7.62x51 (.308 Win.)

Contents

1. Weapon theory Page
1.1. Designation and purpose
1.2. Main components and accessories
1.3. Dismantling and assembly
1.4. Cleaning and maintenance
1.5. Functional checks

2. Manipulation

2.1. Loading, reloading, unloading
2.2. Positions of firing, using normal ammunition
2.3. Sight adjustments

3. Technical data

1. Weapon theory

1.1. Designation and purpose

The semi-automatic sporting rifle SIG-AMT is a delayed blowback weapon with stationary barrel and semi-rigid breech.

The cartridges are fed from magazines of 5, 10 or 20 rounds.

A considerably reduced recoil and the bipod which lends the rifle a firm support, improves accuracy of aim in all types of fire.

Next to the normal trigger, in latched neutral position, is a winter trigger. This can be unlatched and shifted into engagement to allow firing in mittens.

In the head of the breech casing is a loading indicator, affording a visual check as to whether the weapon is loaded or unloaded.

2. Main components

The principal parts of the weapon are:

Barrel, bolted firmly to the breech casing.

Breech casing with 2 lock heads, carrying handle, loading indicator, bolt, rear sight and cartridge ejector opening.

Breech with breech head and director shaft, connected by a transverse key.

Rear casing with butt and recoil spring column.

Trigger unit with trigger casing, trigger mechanism, safety catch, winter trigger, pistol grip with cavity for storing cleaning materials and magazine charger.

Barrel casing with bipod, hand rest, and front sight mount.

Accessories

- Magazines for 5, 10 or 20 rounds - Sling
- Pull-through with string and wire brush - Loading indicator holder - Magazine charger - Telescopic sight - Control caliber - Front sight key - Hand guard (upper half)

1.3. Dismantling and assembling

Routine dismantling
- (1) Unload weapon as per Section 2.1.
- (2) Remove butt
- (3) Draw and remove bolt
- (4) Extract breech
- (5) Remove trigger casing (squeeze retaining pin with thumb and forefinger, and slide to the right).
- (6) Separate the breech head from the director shaft by removing the transverse key
- (7) Remove the recoil spring column from the butt.

Detailed dismantling
- (1) Routine dismantling (1-7)
- (8) Detach the sling by unhooking the spring hook from the front sling bracket.
- (9) Remove upper part of handrest
-(10) Unscrew the hand rest screw, and remove the hand rest
-(11) Unscrew and remove the screw from the connector piece of the barrel casing
-(12) Slide the barrel casing forward off the barrel
-(13) Dismantle the magazine
-(14) Unscrew the butt screw
-(15) Remove the butt, together with the end plate and the rear sling bracket, from the rear casing

Assembly

Reverse the above operational sequence.

1.4. Cleaning and maintenance

Rough cleaning
- Clean down the rifle and magazines externally and then grease them.

Routine cleaning
- Routine dismantling as in Section 1.3.
- Clean down all dismantled components, including magazines, and grease them.
- Clean the bore. Caution: Lift the loading indicator and secure it in raised position with the holder. Check and grease.
- Clean and grease the breech and breech casing
- Clean and grease the recoil spring.
- Check over all principal parts.
- Assemble the weapon.
- Perform the functional checks as per Section 1.5.

Complete cleaning
- Detailed dismantling as per Section 1.3.
- Clean, check and grease all components in the same manner as for routine cleaning.
- Assemble the weapon.
- Perform the functional checks as per Section 1.5.

Functional checks

a) Safety catch

Set safety catch to "S" Pull bolt backwards and release Check that the trigger remains locked.

b) Firing action

Set safety catch to "1". Squeeze trigger with left hand. Draw back the bolt with the right hand, and allow the breech to glide forward slowly. Check that when the breech is locked, the hammer is not released. Release the trigger Set safety catch to "S".

c) Pressure point

Set safety catch to "1" Squeeze winter trigger Check several times whether the pressure point can be felt.

d) "Locked breech" gap (similar to head space)

Turn the weapon, without magazine, to direct the magazine opening upwards Perform vigorous loading action repeatedly by hand. Check the gap on the left hand side between the breech head and the director shaft at locked breech position, using the gauge provided.

2. Manipulation

2.1. Loading, reloading, unloading

Charging the magazine

a) without magazine charger:

- Press cartridges singly into the magazine

b) With magazine charger and cartridges in belt:

- Place magazine charger on the magazine
- Place full clip in the magazine charger, and press all the cartridges into the magazine together.

Loading

- (1) Set safety catch to "S"
- (2) Insert magazine
- (3) Perform loading action (bolt)

Reloading (magazine change)

- (1) Remove empty magazine
- (2) Insert new magazine
- (3) Perform loading action (bolt)

Unloading

- (1) Set safety catch to "S"
- (2) Remove magazine
- (3) Perform loading action
- (4) Check that the loading indicator is low
- (5) Set safety catch to "1"
- (6) Squeeze trigger
- (7) Set safety catch to "S"

2.2. Positions of firing, using normal ammunition

The best accuracy of aim is attained in the following positions:

- on bipod

Alternative firing positions are:

- prone, without support
- prone with support
- kneeling
- sitting
- standing

 

2.3. Sight adjustment

- Only make corrections when the deviation off aim has been determined definitely.
- Point of aim is corrected by elevation and lateral adjustment of front sight as follows:
- Slacken the lock screw in the sleeve of the barrel casing.
- Elevation adjustment (using key):
- Deviation below target - Turn front sight to the right
- Deviation above target - Turn front sight to the left
- Lateral adjustment:
- deviation to the left - Shift front sight mount to the left
- deviation to the right - Shift front sight mount to the right
- Tighten lock nut again when the adjustments have been made

3. Technical Data

Dimensions

Calibre 7,62 x 51 mm (.308 Win.)
Overall length of rifle 989 mm (40")
Barrel length 479 mm (19,9")
Rifling pitch 305 mm (12")
Number of rifling grooves 4

Weights

Rifle with hand rest cap 4330 g (9 lbs 10 oz)
Rifle with bipod 4520 g (10 lbs 1 oz)
Empty steel magazine for
- 5 rounds 160 g (5 1/2 oz)
- 10 rounds 210 g (7 1/2 oz)
- 20 rounds 300 g (10 1/ 2 02
Sling, complete 120 g (4 oz)
Telescopic sight with mount 630 g (1 lb 6 1/2 oz)

Ballistic data (average)

Muzzle velocity 790 m/sec (2600 ft/sec)
Muzzle energy 300 m/kg (2170 ft/lb)
Shoulder recoil 0,85 m/kg (5 ft/lb)

Sights

Sight base (rear sight - front sight) 540 mm (21")
Rear sight (aperture type)

- with range adjustment 100-600 m (109-650 yd)
- graduated for every 100 m (109 yd)

Front sight lateral adjustment + 2 0/00

Front sight elevation adjustment ± 2 0/00

Telescopic sight:

- Magnification 4 x
- Scope diameter 25 mm (1")
- Visible field at 100 m 12 m (13 yd)
- Lateral adjustment + 14 0/00
- Elevation adjustment + 23 0/00

Last Modified on May 11, 2000
aalbert@biggerhammer.net