Mehavey states water is the more accurate, and is the basis for all case comparisons that you will find in standard references (and all across the Web). Go figure out what the difference in water capacity for a give case with different amounts of out of round diameters and you'll disagree with this. Look closely on the web and you'll also find top ranked competitors sorting cases by weight. But case water capacity is the one most e-talked about.
The group of 4 folks I know of shooting the .308 Win. (and other cartridges) the best for accuracy (machine rest tested) and collectively having the most Nat'l Championships, matches won and records set, all use cases sorted by weight.
Unclenick, Lapua's been known to package some cases and bullets from two or more sets of coin, cup, draw and shape dies in the same retail box so that two-humped case weight curve is not surprising to me. A friend checked several hundred Lapua match bullets on an optical comparitor and found 4 distinctly different shapes of rebated base and ogive contours on their D46 185-gr. FMJRB match bullets.
US Navy Distinguished Marksman Badge 153
Former US Navy & Palma Rifle Team Member
NRA High Power Master & Long Range High Master
NRA Smallbore Prone Master
Last edited by Bart B.; February 12, 2013 at 11:29 AM.