.280 Enfield...Ahead of its time

[adamjp]

Yes. A whopping 0.16" longer. Seems to me that's more than offset by the SPC's height and width volumes, which are each 0.22" less than for the Grendel case.

But, that's not terribly important. Of far greater impact is the simplification in design of metallic links, which you completely ignored. :confused:

The improved feeding characteristics of the longer, more tapered case are a major plus too.

I completely agree that the 6.5mm bore appears to be the top approach at this time, but I don't agree that the 5.56 is the last word in cartridge or caliber for personal weapons or section weapons.