Greetings!

[WmGardner]

Welcome to the forum WmGardner and thank you for your service! I haven’t shot 600 yard competition and I really haven’t run the numbers to see what weight cartridge will be the most efficient. The 107-108 class of bullets have of little higher velocity with shorter time of flight but a have lower BC than 120-123 grain or 129-130 grain bullets. Making the proper wind adjustment will usually be the determining factor. The Laupa 108 or 123 grain Scenar get very good reviews even though pricey. The 130 grain Berger bullet used in Federal Gold Medal Match ammo might be another top performer. At 600 yards the Sierra 120 grain Match King might shoot as well as the 107 or 123 grain TMK or SMK.

I think you’ll need to just see what your rifle likes.

Here is a link to the 6.5 Grendel Custom Search feature.

https://cse.google.com/cse?cx=0163689474...cu1o&hl=en

Thanks for the advice! In our testing we saw “good” results from the SMK I had on hand. Averaged at 1 1/8” - 1 1/4” groups at 100yds with my most successful loads. The Scenar 108 are performing as well or better than the 123SMK and the 123 Scenar (actually 123.4gr) are performing significantly better than either of those.