The MSBS-5,56 (short for Modułowy System Broni Strzeleckiej kalibru 5,56 mm (Modular Firearm System 5.56mm Calibre) is a selective-fire rifle currently under development as the future service rifle for the Polish Army.

Standard MSBS rifle with underslung bullpup grenade launcher.

There are two basic variants under development, based on common upper receiver: a bullpup version and a standard version with folding, collapsible stock. Thanks to a variety of modules, both variants are to be easily transformed into a carbine, sniper rifle or an infantry automatic rifle. The rifle is chambered for standard 5.56x45mm NATO ammunition, but other calibres could be accommodated with a different bolt and barrel combination.

Initial prototypes of standard and bullpup configured MSBS rifles.

The MSBS rifle has been under development since 2007 by the Military Technology University in Warsaw in cooperation with the manufacturer FB Radom. The rifle is due to enter serial production at the Radom-based Fabryka Broni and enter service by the end of 2014.

MSBS rifle featured at 2013 SHOT Show