I've been carrying a 442 pretty much 100% of the time. Although I'm going through a change lately and starting to carry other guns. So my answer SHOULD be the revolver. But I carry 15 extra rounds. If I really had to choose between those 2 guns and NO RELOAD, I'd choose the .380. Given it was reliable.
At least I think I would.... it's not an easy choice to make. Why can't you have a reload? I mean either one does not make much of a footprint. Right now I carry 2 speed strips with 4 rounds, a speedloader with 5 and two loose rounds for an even 20. And none of them are bulky at all. You could argue the speedloader is bulky, but it's pretty small. You could fit at least 1 speed strip or one extra single stack mag pretty easily somewhere. Put it in your shoe for crying out loud. Remember those shoes with the pocket? Roos, or something like that.