About 20 years ago me and my nephew tried about every 22cal possible. we tried a 22-284 that is just slightly larger capacity than a 22-6mmAI........you will never get the speeds you think you will and the barrel will be half shot out by the time you work up a load. Biggest I will go ever again is a 22-250AI with 1-8" twist. about 5 times the barrel life and you give up very little velocity.