The .243 AI and the 6MM-06 are also good high performance .243's. The .243 AI will provide about 200 fps more speed than the regular .243. . . . .240 Weatherby offers about 300 more . . . . 6MM-284 and 6MM-06 are close to 400 more. I find the 6MM-284, with its shorter fatter case, to be a little more accurate and slightly more effecient in terms of pressure/velocity than the 6MM-06. But they are very close.

One of my customers summed it all up about fifteen years ago. He got his 6MM-284 with a 26" Hart barrel delivered and sighted in a couple days before a Wyoming mule deer hunt. On the way back to Colorado, he called me from his cell phone. "What a vicious little gun . . . " was his opening comment.