M1 carbine? You got to be kidding. limited to 150 yards for realistic accuracy and power. P@$$ ant cartridge with a bad record of stopping power. Why go backwards? HK 416? Yawn. Just a redesigned upper that will cost us taxpayers 3x what it’s worth. Not impressed by Sig, either. Snooty people to deal with. Let’s stay USA stuff, please.You wanna go old school? How about the AR-18 (aka: AR-180 in semi), maybe with a slightly heavier barrel and a rail system. Or a stoner, has a quick change bbl. Both reliable as heck, and reasonable to mfg.
A very much under-rated weapon, IMHO. Long before the Grendel was even being talked about, I thought a great service cartridge (ammo weight vs. ballistic performance) would have been a stoked up .250 Savage. Factory loads were always at reduced pressures to accomodate the M99 lever actions, but loaded for a more robust action I'd be willing to bet it would do everything the 6.5 Grendel would and then some (albeit in a slightly larger case). The .257 WSM is one helacious little round, albeit too fat for practical military use...nevertheless, I think the Grendel is an awesome little compromise.
Wish I'd have thought of it.