Beretta Web - Submachinegun MP12S

A Front cap catch - G Rear cap catch
B Front cap - H Rear cap
C Front sight - I Automatic safety
D Cocking handle - LTrigger
E Selector-safety - M Magazine latch
F Rear sight

- 1e….Devices

The 12 S Sub-machine Gun is provided with:
- closing device consisting of the telescopic bolt (blowback) and the recoil spring
- firing device consisting of: sear mechanism percussion mechanism
- extraction and ejection device consisting of: extractor (extractor hook) fixed ejector
- three-position selector-safety device: ordinary safety - semiautomatic fire - full automatic fire, controlled by a single lever. The ordinary safety immobilizes the automatic safety on the grip which, in turn, blocks the trigger
- the automatic safety device on the grip which blocks the trigger and prevents the opening of the bolt by means of the bolt stop tooth
- aiming device consisting of a two-position rear sight (up to 100 meters - up to 200 meters) and a front sight adjustable for elevation and windage
- folding stock.

Operation : Full automatic or semi-automatic: the weapon fires from an open bolt position.
System of operation : Blowback
Caliber : 9 mm. Parabellum
Ammunition 9 mm. : Parabellum NATO standard
Muzzle Velocity : (V0,5) 430 m/sec. approx.
Bullet Energy : (E0,5) 77 Kg/m. approx.
Cyclic rate of fire : 550/650 RPM
Length : (metal stock folded) 418 mm.
Length : (metal stock extended) 660 mm.
Barrel length : 200 mm.
Height : (without magazine) 180 mm.
Height : (with 32 round magazine) 244 mm.
Weight : (without magazine) 3.2 Kg. approx.
32 round magazine weight(empty) : 0.230 Kg. approx.
32 round magazine weight (full) : 0.570 Kg. approx.
Barrel rifling : 6 R.H. grooves - pitch mm. 250
Rear sight Two positions for: up to 100m. - up to 200 m.
Front sight : Adjustable for elevation and windage
Line of sight : length 285 mm.
Safety Ordinary : which blocks the trigger through the automatic safety.
Automatic : on the rear grip which immobilizes the trigger and blocks the bolt in a closed position.
Finish : With epoxy resins resistant to corrosion andwear. Black glossy plastic grips.

- 1g….Features

SELECTOR
The new selector allows for an extremely easy, precise and safe selection of three positions, namely: semi-automatic fire, full automatic fire and safety.

SIGHT
This new device (considerably strengthened) which has a higher degree of precision in aimed fire and greatly increased - accuracy, possesses the following advantages:
the possibility of regulating the aim for ranges at 100 and 200 meters by means of a simple 90" rotation of the rear sight mechanism;
- the possibility of regulating the aim both in elevation and windage by adjustment of the front sight only.

REAR CAP CATCH
The introduction of the new rear cap catch has the important advantages of:
- greater maneuverability of the rear, cap and the catch itself, for purposes of both stripping and assembling;
- the provision of a lock in position for the catch indicating the exact degree of tightening required for safety in the weapons' performance.
Should the rear cap not be completely screwed on and locked in position, the catch would remain raised, immediately indicating faulty tightening and at the same time interfering with the alignment of the sights.

FOLDING STOCK
The new folding stock has a much more robust and functional butt plate. It has two catches which firmly lock it in either an « open» or «closed» position, making it more practical and allowing for greater firing precision.

SEAR BLOCK
The new system permits the elimination of a possible «double shot» when the selector is in the semi-automatic firing position. This is due to the disengagement of the trigger-ratchet which is effected only by the regulated movement of the sear block joint which, in turn, can occur only once the bolt has been released.

EPOXY RESIN FINISH
The exterior surfaces of the weapon which might be particularly liable to corrosion are well protected (after phosphate treatment) with a light coating of epoxy resin. This treatment gives the surfaces the best protection possible from outside elements.

Before use, check to see that the 12 S Sub-machine Gun is perfectly clean and lightly oiled.
The 12S Sub-machine Gun is used in the following way:

BOLT IN A CLOSED POSITION

1) Insert a full magazine.
2) Holding the weapon by its rear grip, pull the automatic safety. The manual (or ordinary) safety must not be turned on.
3) Pull back the bolt by means of the cocking handle until it remains open. The weapon is now ready to fire.
4) Always keeping the automatic safety pressed, pull the trigger. - lf the selector lever is in S position (semi-automatic), after having fired a shot the bolt remains in an open position.
5) Pull the trigger in order to fire again.
6) lf, however the selector lever is in R position (full automatic), the bolt automatically moves backwards and forwards and the weapon continues to fire as long as the trigger is kept pulled or the magazine contains rounds.

- 3a….Field-stripping

Every time the weapon is used, or at least once a month, the cleaning of the 12S Sub-machine Gun's barrel and bolt is recommended. Proceed with its field-stripping in the following manner:

(BOLT IN A CLOSED POSITION)

- Extract the magazine.
- Pulling the front cap catch, unscrew the cap

- Remove the front cap, barrel, bolt group from the receiver.

- Separate the front cap from the barrel

and hence the barrel from the bolt.

- Pulling the rear cap catch upwards, unscrew the rear cap.

- Remove the recoil spring from the rear part of the receiver.

- In order to assemble, repeat the above steps in an inverse sequence.............. .......................................

- 3b….Barrel-bolt cleaning

Tools necessary for the cleaning of the 12 S Sub-machine Gun:
- 2-Piece cleaning rod
- Swabbing brush
- Flannel cloths
- Detergent and protective oil

BARREL CLEANING

- Assemble the cleaning rod
- Screw the swabbing brush onto it
- Immerse the brush in detergent oil and pass it a few times through the barrel
- Insert a piece of flannelette into the eye of the cleaning rod and pass it through the barrel
- Keep replacing the cloth with a new piece until it emerges from the barrel absolutely clean
- Slightly soak this last clean piece of flannelette in protective oil and pass it again through the barrel

BOLT CLEANING

- Clean the bolt with a cloth soaked in detergent oil after removing combustion residues deposited on the front part of the bolt and in the extractor housing
- Put a thin coat of oil on the bolt itself

- 3c….Front sight adjustment

The Beretta 12 S Sub-machine Gun is supplied with a front sight adjustable for elevation and windage. In order to do so use the recommended special tool.

ELEVATION
Should the weapon shoot high, rotate the front sight in an anticlockwise direction using the special tool.
Rotate it in a clockwise direction should the weapon shoot low.

WINDAGE
Using the same tool, unscrew the front sight strut bush nut and move it, with respect to the axis of the weapon:
- towards the right, if the weapon shoots to the right of the target
- towards the left, if the weapon shoots to the left of the target. Check the tightening of the front sight strut nut once adjustment has been made.

4……..DRAWINGS AND WEAPON PARTS
- 4a….Diagram showing all component parts