Hi. Are you sure it's a .30-03? The '03 wasn't around very long. Mind you, that didn't stop Winchester from chambering 95's in the cartridge. Suspect a 95 in .30-03 will be somewhat of a collector's piece too.
Any .30-03 you find will be collector ammo. You won't find new factory hunting ammo or dies, etc.
However, the .30-03 is just a .30-06 with a 70 thou longer case neck. Same case dimensions otherwise. It used a 220 grain bullet at 2300 fps out of the 1903 Springfield.
You can shoot .30-06 out of an '03 with no fuss, but the accuracy may be poor due to the longer chamber. Sometimes that isn't a big deal. Especially if you get to shoot a Win 95 in the chambering.
You'd best have the headspace checked first too. .30-03 and .30-06 Win 95's are rumoured to be prone to bad headspace.