I would move up to 6mm or something in the 6.5 like the creedmor. you could chamber a 22-250AI in a 1;7 twist and throat it for the long 90gr Berger VLDs but then your stuck shooting only those long high BC bullets. Im in the middle of building a 6x204 Ruger with a 1;8 twist to shoot the 87gr V-MAX and the 95gr SMK's. It should shoot the 95gr somewhere between 3150 and 3200FPS. my friend has a 6x45 shooting the 95 SMK at 2850 to 2900fps. we were out a couple months ago and were smoking rock chucks at 500+, even got one at 640 yards ranged with my G7. Very economical and easy to load for, just necking up 204 brass to 6mm. It's like a 6x47 REM.(6x.222rem mag)but Improved, slightly more capacity and easier to get brass for. Run the ballistics with those High BC bullets and its pretty impressive for what it is if you want to stay on the economical side. after that your jumping up to more powder, 243win on up, 6x47Lapua and so on.