can a vice, wrench and rubber mallet pass?
Do you want the reciever to be usable after the barrel stub is extracted?
You could just torch cut the reciever to get the barrel out.
Use the right tool for the job.
No the reciever is just the stub.
So I can just cut it off? I guess just take care not to cut through to the threading on the barrel? What should I use? A dremel?
Take a sawzall and cut through the barrel and chamber at an angle.
The remaining piece of barrel will unscrew.
Then you weld up the big slot in the barrel left by the sawblade.
Make sure not to get too much weld in the bore or you will have pressure problems later.
Or, just use barrel and action wrenches if you want to re-use either part...