there are reduced recoil loads in every reloading manual
10gr unique or trailboss with a 180gr projectile comes to mind
there are aslo reduced loads with h4895

stuffing a smaller projectile -in a necked down case does not make it superior to the original case -cartidge
especially in the case of the 308win- but it sure does sell more product........
if 260rem is superior
then 243 is even more so
or maybe less.
depending on how you anylize the ballistic coeficent -energy-velocity-data
& what your trying to achieve with the given caliber
you can load the 308 for everything from the smallest varmit to moose-
you can even shoot .224 sabot projectiles in it
if you reload -no reason to change anything.
if you dont & your looking for less recoil
.243win is my choice of necked down 308's
much easier to find ammo for than 260rem if ya dont reload