I know better, figured it was worth asking because:
Some random dude shows up at my work, must be a friend of one of our mechanics, because one of them pulls me aside and says hey you want to buy some guns? There stands this unkempt looking dude who I have never seen before in my life. Getting right down to business...
yo I got a 9MM for sale.
what kind?
Hi-Point.
I'll pass.
yo I got some .380 ammo for sale too.
I don't own anything chambered in .380, thanks.
yo you can shoot .380 in a 9, I do it all the time.
thanks, good day.
cliff notes: random dude shows up and says he shoots .380 in his 9MM Hi-Point and I don't have the heart to call him out, even though I've never heard of anyone doing this, ever, so I err on the side of caution and ask my colleagues.