A generation ago, most reloaders got started in reloading with .30-06 loads in GI brass.
Yes the crimp needs to be removed with a small screwdriver, pocketknife or drill bit. It makes great reloads and will last forever if you anneal the necks every 10 reloadings or so. The internal capacity is less than commerical brass because the walls are thicker, so load them below max. If you feel the need for speed or the need to hotrod, buy a .300 magnum.
If you have live ammo, check the headstamp date. If 55 or earlier, it MAY be loaded with corrossive primers, so clean accordingly. The old stuff will still shoot very well. The most accurate .30-06 ammo that I ever shot was FA 36 NM. I shot several hundred rounds of it in the 60s and never had a misfire.
If you prep a couple of hundred pieces by removing the primer crimp and trimming to length, they will last you the rest of your natural life.