I was finally able to get to the range this morning to do a 10 shot ladder and pressure test so I'll know where I need to start my accuracy, etc, testing. Hornady recommends an 8 twist or faster and the only 243's that have an 8 are my BCA AR 10's, a HB 20" and a LW SS 24"(all testing done with this one). Regardless of powder or charge and/or primers with other loadings and bullets, both barrels love bullet weights 70-100 plus grainers .020" off the lands.
Let me say this, Sta Ball 6.5 is becoming my favorite powder over Varget and H4350 as it seems to give max velocities and accuracy 150-300 fps faster (same barrel length) before hitting pressure in the 22 CM, 6 CM , 6.5 CM and 243.
NOTE: This is for informational/educational purposes and not intended to be used as load data. What's safe in my guns may not be safe in yours. If you decide to use said data than you're doing so at your own risk and you're on your own PERIOD!!!!!
Since there isn't any published AR 10 in 243 data for the 80 VLD-VT, I started at 42 Grains @ 2953 FPS and worked up to MAX of 46.5 grains @ 3445 FPS (started seeing extractor/ejector marks) in 1/2 grain increments.
All data is on the attached target, included but not limited to; Gun, suppressor, bullet, powder, primer, conditions, yardage, etc. Shots 1, 2 & 3 are close together and shots 4, 5, 6, 7, 8, 9, & 10 are close together. I also included a pic of all 10 pieces of brass and if you look closely than you will see the brass with pressure signs.
Now since I know where to start with testing loads at various distances (100-600 yard), under various conditions, etc. It gives me something to work with and it may be a while before I post my findings which includes performance on predators!