I'm curious as to what you guys think of this. I've been hearing about people doing it more and more, but haven't really heard of any serious mishaps happening because of it. I believe the logic behind doing it is that the extractor will hold the case against the breech, so the round will headspace off of it instead of the case mouth (it also allows the firing pin to actually reach the primer).
I'm not suggesting anyone do this, or that it's safe, but beyond the blanket statement of "only shoot what cartridge your gun is chambered for", what are the possible dangers to doing this?
And before anyone asks, no. I do not plan on doing this regardless of whether it's safe or not. I do not own a 40 S&W, and 10mm brass is pretty inexpensive as it is, so there would be no benefit to me doing it. I'm just curious about it.