Beta C mags have to kept very clean and lubricated with graphite to be reliable, and I would not take one into places where they have to be bumped, dropped, ran into barricades etc.., they should have made it belt fed, they did have belt fed HK G3's, model 51 I think, I bet this will evolve into one, 65 and 85 rpm in a machine gun??? MISPRINT, The 249 is 750-1,000 rpm, probably meant the M27 is 650 rpm, there is a 150rd mag by Armatac, weighs 8lbs loaded, supposedly good stuff but I don't know, does not make sense to me, cool assault rifle, crappy Squad automatic weapon replacement. IMHO, especially with a 30rd mag, maybe more reliable, but accuracy is doubtful better than an M4 using the same ammo, and I would bet the designated marksman M4's with 77 grain pills is superior.