Stillbeeman: The MAIN reason to shoot 100 grain bullets in a 260 Remington is the exceptional and reliable lethality they induce on Deer and Antelope size game.
The weight of a bullet is NOT the main factor in lethality on Deer and Antelope sized game!
IF weight WERE the main factor in lethality on Deer and Antelope sized game then everyone would Hunt them with a 700 Nitro Express and its 1,000 grain bullet!
TRY the 100 grain bullets from a 260 Remington on Deer and Antelope sized game for a few years and see what I mean.
Hold into the wind
VarmintGuy