I hear that the Matra at MacDill is a training/acq round delivered in a 'live' box by mistake…..
Re Red Air, there's a number of factors in play. Primarily, as RAFEng points out, Aggressor flying wears out aircraft quickly - especially if you're trying to prop up your Tac Air front line with ageing aircraft as you didn't get as many Gen 5.1 (F-22) as you wanted and the Gen 5.2 (F-35) is still building its force structure. There are two other issues; the US Military is trying to drive down headcount across the board. This is because it's getting increasingly hard to recruit high-calibre individuals for certain roles and, with life expectancy increasing, the pension burden becomes greater year on year. Secondly, RedAir is a specialist skill, which does come at increased risk; the DoD has trained the pilots, amortised the cost over their service, and now gets to retain their skills and knowledge whilst passing the operating risk to a 3rd party - if there's an accident, whilst tragic if fatal, it doesn't potentially go down as a shortcoming in a CO's Efficiency Report. Finally, if an F-16 is fighting an F-16 in a fancy paint job it's not really DACT is it? The F-5 was a reasonable facsimile of Gen 2/3 Soviet hardware, but even then the USAF felt it needed the exotica of the 4477th to train selected crews effectively. Contract RedAir enables their pilots to 'fight' against a number of different types, fulfilling different (and scaled) threats - the Mirage F1, Kfir, A4, L-159, Hawk etc are all well embedded - and there may well be 'exposures' to 'other' aircraft still going on somewhere….. Ironically, the much-promised F16 AdAir aircraft have never actually appeared….