The MSBS-5.56 Radon is in the running to become the next standard-issue assault rifle of the Polish Army. The weapon began development in 2007 and has evolved along modern lines to become a modular system - its core components to be featured in an assault rifle design as well as make up the basis of a carbine, sniper, and squad support weapon form. In keeping with contemporary offerings seen elsewhere, the MSBS will carry full accessories support by way of rails for the mounting of various optics, aimers, grips, and the like to allow the infantryman to customize his rifle for the given mission. As it stands today, the MSBS is being considered in both a traditional rifle form (with the magazine feed ahead of the pistol grip) and a bullpup configuration (the magazine feed and action set aft of the pistol grip). Both forms are chambered for the 5.56x45mm NATO standard cartridge and fire from a curved, STANAG 30-round detachable box magazine.
The modern Polish Army relies o the KBS wz.96 which arrived in 1997 to replace aging stocks of AKM-related assault weapons - all related to the original Kalashnikov AK-47 of the post-World War 2 years. A new approach was initiated to help produce an all-Polish assault weapon offering from the Lucznik Arms Factory. The end design follows a design more closely associated with the American AR-15/M16 line than previous Kalashnikov guns - the MSBS becoming a gas-operated, rotating bolt action weapon with a short-stroke piston at the heart of the design. Rate-of-fire is listed at 700 to 750 rounds per minute.
The standard rifle form has a weight of 8.2lbs with a 39" overall length. The bullpup form has a weight of 7.5lbs with a 28" overall length. The standard model features a hinged, folding shoulder stock for a more compact form while the bullpup form has an inherently short profile though larger, fixed shoulder stock section. In the bullpup configuration, a full-length barrel is retained and most of its length shrouded by the gun body, the mass of the gun concentrated at the shoulder. One of the notable drawbacks of such a design is the proximity of the firer's face and hands to the muzzle. Firer's do appreciate the bullpup's accuracy and compactness when brought up to the shoulder and many modern armies have begun adopted various bullpup rifle and carbine weapons since the late 1970s - the most famous of these being the Austrian Steyr AUG.
Various models are now made available under the MSBS name. The basic, conventionally-arranged assault weapon is the MSBS-5.56K. The MSBS-5.56B is the bullpup-configured model. both major forms have five subvariants between them covering the basic rifle model, another supporting a 40x46mm underbarrel grenade launcher weapon, the shortened carbine form, and light machine gun model and a Designated Marksman Rifle (DMR) model. Barrel lengths span from 10" to 16".
The MSBS-5.56R was developed as a parade model to primarily fire blanks. The MSBS-7.62S supported the Soviet 7.62x39mm cartridge and the MSBS-7.62N supports the 7.62x51mm NATO cartridge, the latter to fulfill the Battle Rifle role is required.