Yep, I scrapped the 3 twist and went to the 6.5 twist. I have published lots of data on this site, for 6.5 twist, since I had both 3 and 6.5 twist at the same time.
The 3 twist is ridiculously restricted, and mine an early barrel that should have never left the manufacturer, with torn and galled rifling, with a fuzzy metal slivers appearance throughout the bore.
It needed to be aggressively lapped before even shooting it.
The 6.5 twist makes a dual purpose 8.6 Blackout with accuracy and speed not attainable in the 3 twist.
You can shoot the cheapest lead bullets as fast as the 8.6 can run them, with out fear of blow ups. Same is true of tbe 350 gr Maker you're not limited to 1000 fps as per Maker instructions or they blow up. You can go way above that without fear of destroying your muzzle devices.
The 8.6 Blkout is a good cartridge with the 6.5 twist, no worries.
Accurate and a full dual purpose cartridge with no drawbacks like the 3 twist, a complete mistake IMO...
Here is my experience with the 3 twist following early reloading data... it took Faxon months to take down after many of us complained about it being dangerous.
Destroyed the muzzle brake, and magnetospeed bayonet, with their recommended load data.
The 6.5 twist does NOT have this problem, my 3 twist has been scrapped.
I have data on Barnes 160 gr supers to 350 gr Subs.
I recommend Alpha 8.6 Brass especially for bolts, in the 6.5 twist, for consistency and added velocity for that platform.
I use hybrid cases for my high performance loads, but Alpha brass will work well for those not interested in hybrid cases...mostly for bolts, autos take a bit of tuning. This has all been discussed in full.
Short barrels will not be able to attain these high velocities, but velocity and accuracy can be greatly improved with the 6.5 twist.