Just an interesting point of reference, my National Guard unit had M60's until we were deactivated in 1996. M113/M901's too. Kickin' it old-school we were :)

I can go one further, the national guard armory across the street from my cousins house had M48s it used well into the late 80s and early 90s, and then in the 90s did they start getting M60s.

I would think that the Russian warplanning staff that did not target anything smaller than say DPMS or Microsoft would earn themselves shots in the back of the head.