Anyone have experience running gas shielded flux core without gas?

I've got a 33-pound spool of flux core that requires gas shielding and no gas. I'm running it in a miller 250x. I've ran a couple of beads with it and it seems to have good penetration and the beads don't look half bad. Any input on this would be appreciated.

I guess if you're happy with the result and it's a non-critical application, then go for it.