Having watched The Odd Angry Shot I was puzzled by the number of M-16s on show, given that the Aussie forces were a primary SLR (Lithgow variant) user at the time and all the way forward until 1988 when the licence-built Steyr AUG (the "AusSteyr") replaced it. In TOAS the guy lugging the radio about has the M-16, ostensibly as a lighter weapon with lighter ammo to offset the load of the radio and batteries on top of his personal field kit, and the rest have the SLR or, if the squad gunner, an MG. I.e. One M-16 per platoon.On Netflix, Danger Close. Film based on an incident(s) during the Vietnam War in 1966 The Battle for Long Tan when Aus/Nz troops went up against a far superior number of VC. Plenty of action and annoying incompetance of HQ top officers. What I couldn't get my head round was the use(if factual)of different weapons/calbre used by blokes in the same unit. I ended up about half way through doing the old fast forward thing as it was pretty obvious how things would pan out. Worth a look but don't expect an epic blockbuster.
In DC there's several Owen SMGs in play, too.
Edit to add: in the 1985 Screen 2 drama "Contact" by Alan Clarke (ostensibly a fictionalised account of his own experiences on active service in Northern Ireland) the radioman also carries an M-16 albeit with an M203 attached - so could have been to give the platoon a grenade launcher without the operator of same being diffy a personal long weapon (i.e. in lieu of the M-79) whilst allowing the operator a lighter load against the weight of the comms kit? Also to give the platoon a light weapon capable of automatic fire to supplement the MG (also seen in the drama) for, say, when clearing a suspect building? In the drama the platoon patrols open country and catches suspected terrorists moving weapons from a remote farmhouse to a car so the M-16 would have been useful for securing the house, with the selector on auto, perhaps...? Apart from the MG gunner and the radioman everyone else appears to have the SLR - no Sterlings in sight.