Nope. In international law they're light weapons. From the Wiki entry:
In international arms control, small arms include revolvers and pistols, rifles and carbines, assault rifles, submachine guns and light machine guns. Together with light weapons (heavy machine guns; hand-held grenade launchers; portable anti-aircraft and anti-tank guns; recoilless rifles; portable launchers of anti-aircraft and anti-tank missile systems; and mortars of calibres of less than 100 mm), they comprise the Small Arms and Light Weapons (SALW) protocol.
It isn’t Intl law, it is the UN arms protocol bs that they use to control civilian possession from 2005. Army and the Corps consider .50 small arms. Since you showed USN they do as well.