6.5 MPC

SSK has introduced the 6.5 MPC (6.5mm multi-purpose cartridge) as another alternative to the 5.56mm round.

David Crane @ Defense Review does as good a review as is possible without actually firing a round.

He points out the advantages of the 6.5 MPC vs. the 6.8 SPC: Ease and cost of conversion (weapons conversion), ammo capacity, and ammo weight (ammo carry capacity at a given load weight).

Unfortunately, there are no signs Uncle Sam will be changing the 5.56mm to anything (6.5 MPC, 6.5 Grendel, 6.8 SPC, or what have you) in the foreseeable future.