I'm trying to decide between AR cartridges for coyotes/pigs/targets. I was originally thinking of building an AR-10 but that would be heavier and more expensive than building just an AR-15 upper. All of the load data in the attached chart (Except 6mm ARC & 22-250) came from the Lyman AR Reloading Handbook 2nd Edition. The 6mm ARC data came from Hornady's 11th Edition reloading manual. The velocities i used are the average of the max velocities for each powder listed. I then looked up velocity vs barrel length comparisons for each cartridge and adjusted the velocities so they're all roughly what would be found in 20" barrels. Does anyone have experience with 6.5 Grendel or 6mm ARC? The 6mm ARC doesn't seam to offer anything over the Grendel unless I'm way off on my velocities. Grendel ammo is also a lot cheaper and more available. Let me know your thoughts.