Never had an O6 AI, but have a few others. Except for the 250AI, few really move the velocity meter enough to matter. Frankly if your striving for velocity, there are lots of bigger 30's, your 300wby near the top of the list.
For me the beauty of the AI's is in low case stretch. With an AI if you keep the pressure under control, you can use a collet die and rarely ever trim. Every now and then I bump the shoulder with a body die and trim but its rare. This makes more sense as the cost per case gets higher, but O6 brass is fairly easy to find and cheap.
I wouldn't AI it, if I wanted more than an O6 could deliver and less than the wby.. Id trade for a 300wsm (or a H&H if that lights your fire)
