Experimental prototype SMG USSR by sanmelody


									Experimental prototype 1130 – SMG - USSR

WEAPON                          ROF   DAM     PEN            BLK           MAG            SS/BRST        RNG
1130 – one hand                 10    1       nil            1             var            2/6            10m
1130 – two hands                10    1       nil            1             var            1/5            10m
ROUND                                                        9mmP or 9mm M
WEIGHT                                                       1kg

Alexey A. Konovalov,
member of the Russian Academy
of Missiles and Artillery,
author of the experimental
prototype # 1130.

                            THE NEW PRINCIPLES
                        OF BUILDING A ROTARY BOLT:
                     OF THE MAKAROV PISTOL
                     The rotary (sliding) bolt has become popular in the calibers of automatic small arms as, in
                   addition to its main function of locking the barrel bore during the shot, the bolt performs a
                   number of other functions:
                   - accumulator of energy required for performance of automatics;
                   - it accommodates extractor;
                   - it performs as a ramming device;
                   - it holds the next round in the magazine.
 Some of these functions can
be carried out by the bolt
carrier as well.

In order to accumulate
enough energy during a shot,
with the limitation of velocity
of collision of moving
components at hand, the bolt
(bolt carrier) should be heavy.
In order to avoid increasing
the width of a gun, the bolt
should be long enough. If we
could limit the width of the
bolt to the function of holding
the next round in a magazine,
its section specified as "À",
shall be unnecessary (Fig.
  The bolt needs the amount of travel "À", which serves, on the one hand, to synchronize in time
the motion of the bolt and the feeding the cartridge into the line of ramming. On the other hand,
"À" is required to adjust the rate of fire. The second factor is predominant in most of the cases.
As a result, the receiver [automatic housing] tends to acquire excessive dimensions, and makes
the entire weapon's system rather extended in terms of longitudinal sizes. The PPSh - the
system taken as classic - has a 270-mm long barrel. The internal size of the receiver that
houses automatics is 350 mm long. Thus, the excessive length of the bolt equals 120 mm, while
its excessive travel (amount of travel of bolt's face behind the cartridge's head) is 60 mm. By
eliminating bolt's excessive length and travel, the receiver could have been reduced by 180 mm.
  The method of reducing the amount of bolt's length is materialized in the UZI submachine gun
by locating the "l" portion of the bolt above the barrel (Fig. 1b). Such a scheme has become
common in such weapon systems as Ingram and Steyr.
  By reducing the amount of bolt's travel over the cartridge head to the level required for
synchronization with feeding, we increase the rate of fire. This is exactly why most of the
modern submachine guns feature the rate of fire upto 1,200 rpm. It should be noted, however,
that the spread of hits in a burst is optimal if
the rate of fire is around 450 rpm.

  In the following scheme (Fig. 1 c) the travel
of bolt over the head of the cartridge (overrun) can be eliminated at all.
Bolt 1 (bolt carrier) consists of the two parts that are firmly put together by means of a one-way
link. The reverse direction of the link is spring-loaded (Application # 96112400 (018160), author:
A. Konovalov. Bulletin of Invention # 25 of September 10, 1998).
When the shot is delivered, the case (piston rod of the engine) transfers pressure onto the bolt
(slide). The two components, due to the rigid linkage, are moving as a single piece. As soon as
the bolt covers the amount of travel sufficient for stripping the next round, the slide is stopped
and retained in this position by spring 3. Further motion is performed only by the inertia body of
bolt 2 (inertia mass). Reaching the point of impact at the rear side of receiver, the inertia body
returns into its initial position by means of spring 4. On its way back, the bolt follows inertia body
2. Here, the amount of travel performed by the inertia body is significantly greater that the
amount of travel performed by the bolt in the two previous cases. This phenomenon reduces the
rate of fire. Furthermore, separation of the bolt recoil impact into two cycles reduces its effect on
the shooter, which helps reduce the spread of hits.
  The above scheme makes it possible to reduce overall length of receiver to the size of two
lengths of the cartridge. Further reduction of the size of receiver is also possible, provided the
bolt is free of the function of holding the round in the magazine. This, however, hardly deems
practical as the construction may become too complicated.
 For the purpose of proving the above statements, an experimental prototype of a submachine
gun was devised, based on the Makarov PM pistol. Its overall length and width remained intact,
while the height is 20 mm greater. The overall (empty) weight of the weapon is 1,020 g. The
weight of moving parts is approximately 400 g.
 Despite such miniature dimensions, the weapon features the rate of fire of 950 rpm - the factor
proves functionality of the elaborated scheme.
Considering that the submachine gun chambered for the PMM (9x18 mm) or Parabellum (9x19
mm) cartridges should have barrels from 150 to 160 mm long, we can build an automatic
weapon 220 to 230 mm long, featuring the rate of 600 to 700 rpm. In such a weapon, we can
use an additional folding (front) grip or a buttstock similar to the Mauser or Stechkin pistols.

 Alexey A. Konovalov,
Russian Academy of Missiles and Artillery.

                       Prototype 1130, field-stripped.

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