Double Naught Spy
Sus Venator
I vote for the 6.5 Grendel, but and a big BUT, just try to find new cases to reload at any price. I reload all my own ammo!
It really isn't that hard to find new brass.
https://www.druidhillarmory.com/store1/6-5-Grendel-New-Starline-Brass-p413717138