12-04-2011, 09:30 PM
I would actually look more seriously at a 130gr projectile minimum for an LMG, if not 140gr like the x55 Swede used. Since COAL isn't an issue for keeping within an AR15 mag length/receiver, and you can design the bolt from the ground up as a high-strength component, and you won't be concerned with reloading the brass, a 130-140gr LMG military projectile is more than feasible, and can be launched at 2600-2700fps with the right powder specific to that loading after the RDT&E is done on it.
Then drop that into a constant-recoil LMG, and you have game day as far as capability is concerned. A 2600fps 140gr 6.5mm FMJ or MP projectile will start to out-gas a 147gr M80 at 300yds, even though it starts out 200fps slower. The 144 FMJ is another option that really smokes 7.62 at distances where GPMG's really come into play.
It's definitely worth pursuing in my book.
Then drop that into a constant-recoil LMG, and you have game day as far as capability is concerned. A 2600fps 140gr 6.5mm FMJ or MP projectile will start to out-gas a 147gr M80 at 300yds, even though it starts out 200fps slower. The 144 FMJ is another option that really smokes 7.62 at distances where GPMG's really come into play.
It's definitely worth pursuing in my book.