The more accurate of the two barrels is the one that'll give you the better accuracy. Could be either, but you're speaking of two different issues here. Really, kind of luck of the draw with regards to accuracy with two different barrels, even from the same maker. Seen plenty of incredibly accurate light weight barrels, and I've seen some heavier contours that were total duds. Wasn't the weight or contour that made the difference (unless the gunsmith screwed something up in doing the chambering), but how well the barrel was originally made to begin with.
As for ther range issue, the 26" will give you a bit more, simply due to it's having a better expansion ratio. Little bit more velocity, hence, range, but it's probably nothing I'd lose too much sleep over. The real question here is, which one do you like better?
Kevin Thomas
Lapua USA