Where do you find the "substantially more case capacity" that you speak of?
The 260 holds 54 grains of H2O and the 6.5x55 holds 56 grains of H2O. What is a 2 grains capacity advantage, 3.57%, going to get you?
Assuming that the 1 to 4 velocity increase to case capacity increase rule of thumb is accurate, a 3.57% increase in case capacity would calculate to a velocity increase potential of 0.89%.
At 3,000 fps, 0.89% is 26.7 fps. Fast barrel verses slow barrel verses higher/lower outside temperature verses ???? territory.
Love the 6.5x55, currently have 9 of them, but the numbers don't lie. The only reasons that I, personally, would opt for the 6.5x55 over the 260 are:
A. The rifle that I want isn't available in 260.
B. I must be able to shoot bullets over 140 grains without having to seat them more deeply into the case. COAL issues you know.
C. I was going to use it in Europe or Africa, where 260 ammo probably isn't commonly available and the 6.5x55 Norma and RWS is more probably available.
JEff
my point was it doesnt have substantially more case capacity
