.45 wildcat

[rcmodel]

For about $300 + $400 you could have it drilled and re-rifled.

If the .30 cal muzzle is big enough to have sufficient strength left with a .45 hole in it.

So its a no for the 30-06, but what about the .300 WSM because it has a longer neck then the .300 Win Mag.

One more time.
You need to start out with a rimmed or belted case to set the headspace on something as big as a .45 cal..

Neck length has nothing to do with it.

rc