Too bad you apparently don't do any hand-loading. It would be rather an easy matter to turn your .300 Win. Mag. ballistically into a .30/06 by working up reduced .300 Magnum loads to .30/06 velocities which would naturally lower sensed recoil.
Reloading one's own ammo is not only interesting, but just plain "FUN" as well. And that sez nothing about saving a considerable sum on the cost of your ammo or nothing about developing "
THE" most accurate possible load for both "practice" shooting as well as for .30/06 level hunting loads for your individual .300 magnum rifle.
In addition, if you'd ever decide to go after dangerous game, you'd still have that heavy-hitter .300 Win. Mag. capability which would give you all the "cartridge" you need for such game.
All-in-all, something else to consider.
Strength & Honor...
Ron T.