Modular weapon system

Drawing of Stoner 63 modular weapon system

A modular weapon system (MWS) is a rifle which has components that can be reconfigured to give the weapon different capabilities. For example, the Stoner 63, is a 5.56×45mm NATO, modular weapon system, using a variety of modular components, it can be configured as a rifle, a carbine, a top-fed light machine gun, a belt-fed squad automatic weapon, or a vehicle mounted weapon. Modularity provides several advantages to military organizations, such as allowing units to quickly tailor weapons to meet immediate tactical needs, to quickly repair weapons, and to reduce overall logistical burdens and costs. However, it makes weapons tracking more complicated as weapons can be easily converted into different types of weapons.

Another example of a modular firearm system is the increasingly popular quick barrel change systems, which is found on some new rifles like for example the Blaser R8, Roessler Titan and Sig Sauer 200 STR. These systems simplify the replacement of worn barrels or caliber changes, since they often only require the use of a hex key, thus eliminating the need for special tools and custom fitting by a gunsmith.