I seem to recall hearing that the Detonics 451 magnum extractor from back in those days had a hook that was closer to the breach face. It was "supposed" to act like a kind of headspacing agent, in case anyone did shoot 45 ACP through a 451. As such, it was "supposed" to be similar to shooting 38 specials in a 357 magnum. Before trying any such thing, I would certainly want to make sure that the round was fed up from the magazine, and not dropped into the chamber. That way the rim of the brass should be within the hook of the extractor.

I wouldn't doubt that somewhat confusing issues like this is why the new Detonics USA company says they're not going to make any 451 magnum stuff.

...Deeton