Ummm....sport shooting? Or is shooting at other inanimate objects (targets) still considered "killing and maiming"?
You're still doing damage to whatever happens to be in front of the business end. Obviously you can't kill a paper target, or any other inanimate thing you're aiming at.
I know, context matters, but still, locked, loaded, aimed, and fired, the results are going to be more or less the same. You going to do damage to something. Firearms have purely destructive properties, as is by design.
I also personally don't consider hunting "killing and maiming" in the sense you are referring. I call it grocery shopping.
So if you didn't kill the animal, how did you get your "groceries"? Did you wave your gun around at it menacingly until it willingly gave up some meat?
If you research the history of firearms objectively through reliable resources you'll find that the original "intent" of the gun is somewhat blurry. It is much like the knife, which you implied above was not intended to do harm towards others. The first "knives" known actually predate human fossils, we're talking 3+ million years ago. Who knows what they were being used for, but I feel pretty confident it wasn't to primarily just chop greens in the kitchen.
It's not blurry at all. It was an instrument of war. The Chinese figured out gunpowder, and that they could do more than start fires with it. It's a well known turning point in warfare that rendered the then modern armor obsolete. Terracotta and leather didn't stand a chance against ballistics.
You can do a lot of things with a knife beyond killing and skinning animals (or enemies).
And that comes back to "it matters not the intended use of the tool". Tools don't have intent, people do. Many tools can be used for purposes that they were not "intended" to be. The end user of said tool is responsible for its use 110% of the time, regardless of what the tool was designed to do.
Tools absolutely do have an intended use. You don't buy a screw driver to pound in nails. You don't buy a lawn mower to reroof your house. You don't buy a firearm to stir your spaghetti. Could you do all of those things with all of those tools? Probably, but that isn't what the designers were thinking of when they created them and they won't always be very efficient outside of their intended use.
Tools don't randomly appear without any forethought from their human designers. They have reasons for their existence.