I don’t see the wisdom of replacing a belt fed automatic rifle with a magazine fed one. The idea is for the machine gunner to deny an area to the enemy, and that is hard to do with a mag-fed 5.56x45mm NATO piece of hardware. The SAW had its problems, but it could put alot of metal into an area in a short period of time. This IAR can’t do that.
But then, I thought the E model of the M-60 wasn’t too horrible. And the 7.62x51mm NATO turned cover into concealment pretty well. Never got to play with the M240.
Springfield passed on the MAG as unsuitable for US troops while virtually every other non-Warsaw Pact country found them highly effective. The M240 was reintroduced to the US Army in the late 70’s as a replacement for the M73/M219 series coaxial machine gun found on tanks. For those unfamiliar with the M73 it is easily the most abominable excuse for an automatic weapon ever issued to US troops. It proved beyond all doubt the given enough time and money that Springfield was capable of producing a machine gun more unreliable than the French Chauchat!
The M60 is largely considered adequate only because most folks had no experience with better.