375 Raptor is the best short action / AR10-length cartridge for firing both high BC, supersonic hunting and target shooting projectiles as well as heavy, accurate subsonic projectiles. Efficient powder burn in the .375 bore provides phenomenal performance from short barrels and great results...
My 35 gunner does 2100fps from a 10" bsrrel with a 250gr bullet, but wait for this...............from the ar15 magazine.
A 375 is nice but In the ar10 the best bet is the 358 winchester that, like the 35 whelen for long action rifles, gives magnun type killing power from a very economic and popular casing and bullet assortment.
One can even use 9mm and 357 pistol bullets for practice and hunting for a fraction of the cost and with a huge assortment of bullets.
Shoot as flat as the 308 and 338 federal but with a lot more killing power.
Pretty effective to take even the largest game on this continent like moose and grizly.