The only fixed nozzles I have encountered were 'wildcats', where someone wanted to index an altered nozzle, and used a setcrew through the bowlstem.
I most commonly use a puller made from #5 threaded rod with a .185" cylindrical plug on the end, however, if your M-6 is a Beck replacement with a standard Indian nozzle within it, the puller must be made from wire with the plug silver-soldered upon it (installed pulller in pic).
When nozzles are only lightly stuck, a cable with a plug on the end can pull them quickly, in the style of a gun bore cleaner.
I have found potmetal Scheblers that required to be drilled out because of the dielectric properties, but most bronze bodies will give up the the nozzle with due patience, Kroil and gently heat, and perserverance.
You do not have the required permissions to view the files attached to this post.