So much talk of Dashers and 284s ;D. Both my current F open calibers. Both totaly different in shooting style. With my Dasher I keep my shoulder away and keep my eye on the flags, just tap the trigger when the flags look good. Sometime the Dasher has ridden back in the bags and shot a 10 as it falls out of the front rest.
My 284s have been very different. In 3 different stocks, 4 different barrels, 2 actions, gun hold has been critical for consistant verticle. I find that unlike the Dasher, I have to concentrate on both hold and flags.
Another thing to think about if neck clearance. If you run the same .001" clearance that PPC shooters use, you will probably get more verticle. Scale your neck clearance up to .003"
JHardy, gotta agree with what you say about digital scales causing you to be a grain out, it has happened to me.