New Army "Caliber Configuration Study"

[Tony Williams]

IMO, a new Squad Common Cartridge/General Purpose Cartridge does not need to equal or exceed M80 ballistics, it just needs to provide the same engagement range capability. It seems to me that what's important is hit probability, not any specific trajectory, as indicated by use of the L129A1 and Mk48 weapons.

Yes, as I've mentioned before (in this thread IIRC, but possibly in another - there are so many of them I find it hard to keep track), I regard hit probability as being the key comparator within ballistics, but that does involve trajectory, flight time and wind-bucking qualities. It is not necessary to match the 7.62mm's retained energy, particularly since a smaller-diameter bullet needs less energy to achieve the same penetration.

My understanding is the 6.5 GPC prototype (second from left, in the photo below) delivers approximately the same muzzle velocity from a 16" barrel as 6.5 Grendel (center, below) from a 24" barrel. These two cartridges would seem to be perfectly suited to making your case.

Can you refresh my memory as to where that one came from, please?