With regard to twist, I shoot a 6mm-06 built specifically to shoot the 105 Berger. I had planned on a 1:8 twist but my builder (Kirby Allen) convinced me to go with the 1:9. He found the 1:9 stabilizes well at 6mm-06 velocities so I took his advice. Easily sub 1/2 MOA with several groups in the .2s, .3s, and .4s before I stopped punching paper and switched to live critters and long range rocks. Light recoil, kills with authority, and great accuracy.
My 25" Bartlein will push the 105 at around 3400 with several powders. I found I got lower ES with RL23 and slowed them down to about 3300 as I simply don't need the extra FPS and thought I would help brass and barrel life at lower pressures.
A 95 berger with a 1:10 is a good option. I have seen them shoot in .243s at much lower speeds. I would personally take a hard look at an 85 TSX or 90 accubond if shooting a 1:10 .240 inside of 4-500 yards. You can get them screaming within ranges where BC won't make much difference.
