Easy mistake!
I think the only damage you might be looking at would be blood stains.... if there are none you are almost for sure OK. I have fired .380's in a .45. Of course the case splits and it's dangerous as hell and stupid (this was a long time ago when curiosity overruled sense). Even though the .40 is a lot more powerful than the .380, there should not be any damage to the gun since the discharge isn't even completely contained. I'm guessing the cases did not rupture (or you'da definitely noticed). Just give it all a once-over to make sure there's nothing in the barrel or chamber, and go on back to the range.
I think the only damage you might be looking at would be blood stains.... if there are none you are almost for sure OK. I have fired .380's in a .45. Of course the case splits and it's dangerous as hell and stupid (this was a long time ago when curiosity overruled sense). Even though the .40 is a lot more powerful than the .380, there should not be any damage to the gun since the discharge isn't even completely contained. I'm guessing the cases did not rupture (or you'da definitely noticed). Just give it all a once-over to make sure there's nothing in the barrel or chamber, and go on back to the range.