6.5 CM takes over for .300wm and .308? How about 6.5PRC

[Azbuilder]

http://soldiersystems.net/2018/03/23/ussocom-adopts-6-5-cm/

https://www.militarytimes.com/off-duty/gearscout/2018/05/08/homeland-security-shooters-are-dumping-308-for-this-long-range-round/

Is this the only reason the 6.5PRC exist's?
Hornady has a video from George Gardner explaining the purpose. Basically, it is the longest BC bullet you can safely push to 3150fps in a short-action (in order to meet the rules for sub-.300 caliber rifles in the Precision Rifle Series). Or is it that the Creedmoor easily fits in a AR-10 form factor?
Then there's the military MK21 Precision Sniper Rifle (PSR)MSR that is in 300wm/338lapua/308 and now ? I would like a short magnum AR-10 in 6.5PRC, but without a total custom

 

[samnev]

I don't do enough long range shooting to justify another rifle, dies, projos and a new powder 4350 which is hard to get to justify the 6.5 CM.

 

[Azbuilder]

Now the Marines go with .300wm. Hmm , so everyone is going to use a different caliber?

https://www.tactical-life.com/news/marines-mk-13-rifle-nightforce-atacr/

 

[Steve_In_29]

The Marines have similar but not exactly the same views of sniping as the Army does so it's not surprising their choice in ammo differs. Though I believe they also have several types/calibers of rifles to use as the situation dictates.