30cal bushing question

If the 308 and 300NM are both Redding dies I'd say yes to your question.

I have a Whidden 300 NM die that uses Redding, RCBS, and of course Whidden bushings. I think most neck bushings are interchangeable, but depends on your die. The neck wall thicknesses for the 300 NM cases (Peterson/Lapua) were thicker than the Peterson 308 Win cases I load. So, needed to buy a bit larger diameter bushings.

Make sure you measure the resulting necks. My Redding bushings seem to all size down more than what they are stamped for so it’s a bit of dealing with it or playing musical chairs finding the right combo.
You should be able to swap in a Wilson as well. The neck bushings that don’t also have the shoulder cut in are pretty interchangeable.

But yeah, 30 cal is 30 cal, the die is what holds it in the right height position.