Country of origin
5.56 x 45 mm
3.4 ~ 3.55 kg
Length (with folded stock)
Cyclic rate of fire
700 - 750 rpm
Practical rate of fire
40 - 100 rpm
Range of effective fire
~ 500 m
The MSBS (Modulowy
System Broni Streleckiej) is a new Polish family of modular infantry
weapons. It includes assault rifles both with conventional and
bullpup layout, that have many interchangeable components. The MSBS
family was developed to replace the older Polish Army weapons, such
as reliable but out-dated
assault rifle, based on the Soviet
The MSBS family of rifles was developed by Polish
Military Technical Academy and local Lucznik arms manufacturer.
Development commenced in 2007. First prototypes appeared in 2009. In
around 2012 Polish MoD acquired a small number of
Bushmaster ACR assault rifles for trials and evaluation. These
were used by the Polish special forces in Afghanistan. That was a
turning point, when prototypes of the MSBS were significantly
redesigned and received many features of the Bushmaster ACR. The
MSBS can be even seen as a Polish clone of the ACR. It
looks like initial production of MSBS rifles for the Polish Army
trials commenced in 2014. These assault rifles are used in small numbers
by the Polish armed forces and ministry of internal affairs. This
weapon is still in development and as of 2016 new versions continue
There are two
basic variants of the MSBS, based around a common receiver. Version
with conventional layout and a folding stock is intended as a
standard-issue service rifle of the Polish army, while the bullpup
version is intended for special forces. Both of these assault rifles
are gas-operated, selective fire weapons. Internal mechanics strongly
resembles that of the
Bushmaster ACR. Initial versions of the MSBS were chambered for a standard
NATO 5.56x45 mm ammunition. In 2014 a version chambered for a
Russian 7.62x39 mm ammunition appeared. In 2016 another version chambered
for standard NATO 7.62x51 mm ammunition appeared.
receiver, along with internal components, is common for both
versions of MSBS rifles. Both stock versions are attached to the
receiver using cross-pins.
of this weapon allows easy replacement of the barrel and other
components. Due to modularity both versions of MSBS rifles can be
transformed into carbines, light machine guns, or designated
marksmen rifles. A baseline assault version has a 406 mm (16") barrel,
carbine version has a 256 mm (10") barrel, light machine gun version
has a 406 mm (16") heavy barrel for sustained fire, while the
designated marksman variant has a 406 mm (16") precision barrel and
a two-stage trigger. These variants are common both for conventional
and bullpup versions. Also assault rifle with conventional layout
can be converted into bullpup layout and vice versa. The main goal
behind this modularity and interchangeability of parts was to reduce
production costs and to simplify logistics. Fewer parts are needed
to be stored. Furthermore a baseline assault rifle can be quickly
adapted for a variety of roles. In combat a standard assault rifle
can be sacrificed to repair a light machine gun and so on.
of these weapons are ambidextrous. A safety/fire mode selector
switch is mounted on each side of the receiver and is operated by a
thumb. It has 3 positions for "safe", "semi-auto", and "full-auto".
There are two symmetrical ejection ports for spent cases on each
side of the receiver. One of them is always covered, so ejection can
be set up to either side. Unusually there are two charging handles,
located on either side of the receiver. Magazine release button is
weapons are normally fed from 30-round magazines. These are standard
magazines and are interchangeable with other Western assault rifles.
Also there are Polish 10-, 20-, 60- and 100-round capacity
magazines, developed for these weapons.
assault rifle with a conventional layout has a side-folding and
telescoping buttstock. The stock can be adjusted for length. Version
with bullpup layout has a fixed buttplate. Foregrips of both
versions are interchangeable.
conventional and bullpup MSBS assault rifles have a full-length
Picatinny-type rail for various optics. These assault rifles are
fitted with simple iron sights as standard, however various scopes
or night vision sights can be easily installed. Range of effective
fire is around 500 meters.
40 mm underbarrel grenade launcher can be installed. These assault
rifles can also mount a proprietary knife-bayonet or sound
suppressor. There are Picatinny-type accessory rail for other
accessories, such as vertical grip, tactical flashlight or laser
an assault rifle with conventional layout. The letter "K" in the
designation stands for "Klasyczny" or "classic". Number "556" in the
designation indicates that this weapon is chambered for the 5.56x45
an assault rifle with bullpup layout. Letter "B" in the designation
stands for "Bezkolbowy" or "bullpup". It is also chambered for
5.56x45 mm ammunition. This weapon can converted into assault rifle
with conventional layout and vice versa.
a parade model used by honor guards. This weapon is chambered for
5.56x45 mm ammunition, but can only fire blanks. However as far as
it is a modular weapon, it can be easily converted to a combat
rifle, that can shoot live ammunition.
a version chambered for the Russian 7.62x39 mm ammunition. It is
intended for export customers. It looks that this weapon is
compatible with 7.62 mm Kalashnikov magazines.
a version chambered for a standard NATO 7.62x51 mm ammunition. A
prototype of this battle rifle with conventional layout was revealed
in 2016. The baseline version has a 406 mm (16") barrel. Also there
is a designated marksman rifle with a 508 mm (20") precision barrel
and fully adjustable stock.
plans to develop a 12-gauge combat shotgun, based on the MSBS