I'm going to bed, as it is about 2:30 AM in Omaha and I've got to clean the snow off the drive in about 4 hours.

If we can agree of the following assumption, I will run the numbers sometime tomorrow:

Assumption #1, it is desirable for bullets not to protrude into the case below the bottom of the neck and any protrusion below the bottom of the neck will occupy case capacity that could otherwise be filled with powder. However, a bullet must be seated deeply enough so that it isn't loose and won't fall out of the case in the magazine or while being cycled into or out of the action. Therefore, we will assume that it is optimal, for the purposes of this discussion, to seat the bullet so that its base is flush with the bottom of the neck for both the 260 and 6.5x55.

If we can agree to this assumption, I'll gather that data and run the numbers tomorrow for the following scenarios:

#1, 260 in a standard short action Remington 700.
#2, 260 in a modified short action Remington 700 with a Wyatt's Outdoor extended magazine box.
#3, 260 in a standard long action Remington 700.
#4, 6.5x55 in a standard long action Remington 700.

If I can find the bullet lengths, I'll run the numbers for both the 140 grain Nosler Partition and the 160 grain Hornady.

BTW, since Hornady has discontinued production of the 160 grain RNs, who is making 6.5mm/.264" diameter bullets heavier than 140 grains and longer than 1.290"?

"Better" is always an objective unit of measure.

JEff