The ArmaLite AR-10's heavier cousin, the AR-10/B is an American light machinegun chambered in 7.62x51mm NATO. Mechanically it is but an open-bolt, belt-fed AR-10 derivative, even if quite a few of its parts are not interchangeable. Though much lighter than other machineguns of its calibre, the AR-10/B has a serious problem with overheating, as it does not possess a quick-change barrel. As such, it should be used in short and intense, high-mobility engagements, and not as a traditional machinegun.