I have tried many of the AI cartridges the 243AI is great and works in a short action if you want a magazine. also you can use Lapua brass, the 6AI is also great and works in a short action if you go single shot but need's a long if you want a mag.
Mine were both 1-8" twist's and you could get 100- 150fps more with the 6AI using 105-107gr bullet's.
The interesting thing to me is that both of these rounds gave much better barrel life than my 6-284's
