Welcome to the forum SClearman!
The difference in performance between 6.8 SPC and 6.5 Grendel will be minimal closer than 300 yards. Brass is probably the hardest component to find for the 6.5 Grendel but Starline opens back order at their website every few months. Once back ordered 6.5 Grendel brass usually ships within a couple weeks. Starline might do the same thing with 6.8 SPC brass.
I just checked and Starline is accepting back orders on 6.8 SPC brass. Starline had back order available for 6.5 Grendel brass a couple weeks ago. If you decide to reload for the 6.8 Starline might be a good source for brass.
https://www.starlinebrass.com/68-spc
The difference in performance between 6.8 SPC and 6.5 Grendel will be minimal closer than 300 yards. Brass is probably the hardest component to find for the 6.5 Grendel but Starline opens back order at their website every few months. Once back ordered 6.5 Grendel brass usually ships within a couple weeks. Starline might do the same thing with 6.8 SPC brass.
I just checked and Starline is accepting back orders on 6.8 SPC brass. Starline had back order available for 6.5 Grendel brass a couple weeks ago. If you decide to reload for the 6.8 Starline might be a good source for brass.
https://www.starlinebrass.com/68-spc