I agree it's worth pursuing. It's just that, as presented, the idea raises a couple of questions:
You say that "a 130-140gr LMG military projectile is more than feasible." On what basis do you make that claim? It looks to me like the steel/copper and steel/steel construction being used in American, European, and Scandinavian "green" bullets will result in a ~120gr 6.5mm bullet the same length as the 120gr GMX (1.4"). That makes for a 5.3 L/D ratio. For a 130-140gr it would increase to the 5.8-6.8 range. Is that truly feasible?
AFAIK, the "constant recoil" principle has only been applied to 5.56mm machine guns. What evidence is there to show it is viable for more powerful cartridges, such as your 6.5 Grendel +P+ load? Do you know of any constant recoil 7.62mm machine guns?
ETA: The heaviest copper solid spitzer boattail I could find is a 128gr GSC. Note the very fast twist rifling required to stabilize the 1.51" projectile.
http://www.gsgroup.co.za/264128SP060.html
You say that "a 130-140gr LMG military projectile is more than feasible." On what basis do you make that claim? It looks to me like the steel/copper and steel/steel construction being used in American, European, and Scandinavian "green" bullets will result in a ~120gr 6.5mm bullet the same length as the 120gr GMX (1.4"). That makes for a 5.3 L/D ratio. For a 130-140gr it would increase to the 5.8-6.8 range. Is that truly feasible?
AFAIK, the "constant recoil" principle has only been applied to 5.56mm machine guns. What evidence is there to show it is viable for more powerful cartridges, such as your 6.5 Grendel +P+ load? Do you know of any constant recoil 7.62mm machine guns?
ETA: The heaviest copper solid spitzer boattail I could find is a 128gr GSC. Note the very fast twist rifling required to stabilize the 1.51" projectile.
http://www.gsgroup.co.za/264128SP060.html