Last Spring, USSOCOM undertook a study of 6.5 family cartridges to determine a path forward for Precision Intermediate Caliber Ammunition. Over the last year, USASOC, the primary driver of this initiative, narrowed it down to 260 Remington and 6.5 Creedmoor. Testing indicated that the two calibers performed very closely.

Last month, the command conducted a reliability test, using two incumbent weapons, currently in US service; the FN SCAR Heavy and KAC M110. Two weapons of each type were used, one was in 260 Remington and the other in 6.5 CM. What they found is that both weapons performed just as well and were just as reliable in either caliber.

As both cartridges were similarly accurate and reliable, the determining factor for selection of 6.5 CM would end up being trade space. The prevailing attitude is that there was more room with the 6.5 CM to further develop projectiles and loads.

I don’t expect a major announcement, or any fanfare with this decision. Instead, you’ll begin to see small movements toward configuring weapons to utilize this round.
http://soldiersystems.net/2018/03/23...adopts-6-5-cm/

Interesting, it will be interesting to see which exact cartridges they end up using.