see stubbs and bigc? lol I been tellin you guys that these bullets ARE "that damned good". They do it all and do it all TERRIBLY well. The grooves (or gaschecks) in the bullets are said to reduce bearing surface without hampering sealing ability. So that reduces friction which will increase velocity AND reduce fouling. I've also heard that those very "checks" allow extra copper to "flow into them while traveling down the barrel". Again that reduces fouling whereas otherwise that metal would remain in the bore.

THE best thing there is, it's just that simple!
RA