I don't like Hornady bullets in these speedy new rounds
I wouldn't lump the 6mm ARC into a "speedy" category
I gave my 9yr old son a 6mm ARC for Christmas, it's proving to be accurate. I even sneak it out of the house when he isn't looking

Savage 110 Carbon Predator in a HNT26 chassis
Just been shooting factory ammo so far, have 33 boxes to burn up before I start reloading. The 103gr Precision Hunter is doing just under 2600 fps from the 18" barrel, and 80gr V-Match is 2835 fps. Haven't tried the 108gr ELD Match load yet
lots of bullets on the shelf to try : 58gr Vmax, 70gr Blitzkings, 80gr ELD-VT, 90gr Cx, 95gr LRX, 103 ELDx, 108 ELDm, 110 ATIP. Powders to try : H322, CFE223, Hodgdon LVR, StaBALL Match, Varget, StaBALL 6.5