On the last 6mm Rem AI......
I was shooting a 26" 1-14 twist, custom barrel, 6 groove with zero freebore, .2435 throat. I was fireforming the 70g Ballistic tips with 50.5g of 760 at 4050 fps shooting 1/2" groups. Neck sized the cases, dropped in 51.5g of 760 and was shooting the 70's at 4150 and all I had to do was neck size the cases afterwards shooting tiny little clover leafs.
Next bullet I tried was the 80g Sierra Blitz BT with R#19, accuracy load was at 3800 fps.
It is really amazing how flat shooting the 70g Ballistic tip is at 4150 fps, and I have no idea what the max load for this barrel is. When I shot a bug hole with this load, followed by several more, I called it a done deal with the 70's at 4150 fps.
I did work up a load with 760 shooting the 60's at 4400+ fps with extreme accuracy.
The 6mm AI or 244 AI is a very user friendly cartridge with ease of attaining accuracy loads.
I would advise you to put this cartridge and the 2/684 on a long action or you will be in trouble as your leade grows.