New Army "Caliber Configuration Study"

[Michael]

Not by the US Army, they weren't. The M1919 was classified as a light machine gun, and the BAR as an automatic rifle. (The initials "BAR" are an abbreviation of Browning Automatic Rifle.)

In the context of the ongoing discussion, the BAR was employed as the SAW/IAR of its time, while the M1919 was employed the M240G of its time; hence the terms used are relevant to the discussion.

If you look at the criteria I posted earlier of Light v Medium v Heavy, they also fit the parameters. I will add some additional criteria that I think should be fairly widely accepted;

Light – Employed by single person (BAR, SAW, IAR)
Medium – Employed by a team (M1919, M60, M240G)
Heavy – Employed by a team, but due to system/ammo weight/bulk, normally fixed or vehicle mounted (M2, M1917, Mk19)