During MSPO 2017, the Polish firearms manufacturer FB "Łucznik" Radom has signed a contract with the Polish Ministry of Defense for the delivery of 53,000 GROT assault rifles in standard configuration 5.56mm caliber to the territorial defense forces of Poland.

Grot MSBS assault rifle in standard configuration at MSPO 2017, the International Defense Industry Exhibition in Kielce, Poland.

The MSBS is a modular assault rifle currently developed and manufactured by FB "Łucznik" Radom to become the next service rifle of the Polish Armed Forces. At MSPO 2017, the MSBS is presented with its new name the GROT.

There are two basic variants developed by FB that is based on a common upper receiver including a conventional assault rifle and a bullpup variant. With its variety of modules, both variants can be easily transformed into an assault rifle, carbine, designated marksman rifle or light support weapon.

The GROT assault rifle is available in 5.56 and 7.62mm calibers. It is fully designed and manufactured in Poland. The modular small arms system with quick-change barrel is based on a common upper receiver for a conventional folding stock or bullpup design.

The backbone of GROT system is an inverted U-shaped receiver, made from aluminum alloy. This receiver, along with bolt group, return spring, barrel and gas system are common for both current versions of GROT rifles.

The GROT is operated using short stroke gas piston, located above the barrel, and its gas system has manual gas regulator. Breech lock is achieved by a conventional rotary bolt with seven radial lugs that lock into the barrel extension. Ejection windows are made on both sides of the receiver, and weapon can be set up to eject to either side; this requires partial disassembly of the gun and installation of the ejection port cover on the side opposite the “active” ejection window.

The GROT features ambidextrous safety / fire mode selectors located at the top of the pistol grip, and ambidextrous magazine release buttons located in front of the trigger guard.