what does it look like happened to my cat

I'm pretty sure someone shot my cat with a b b gun. Who does that. My cat was ally cat since birth. Someone found the baby's. He has always wanted to be outside. Comes in to sleep at night when it's cold or to eat. Toby is a tuff cat. He is always fighting with the cats in the alley. So occasionally he'll come in with a scratch of some sort. Nothing serious. We try to keep him in, no such luck. Yesterday he came into eat and the baby said " oh Toby being bad again he got a scratch " I was like is he bleeding. Nope the kids said. He ate and took off like normal. Today I was outside and my cat came to me from the alley to hold. I was like let me see that leg of yours ( just to be safe ) it's not a scratch but a perfect round hole. I'm like that can't be right. When I went to look some more and try to clean it. He took off I can't find him. You think he will be ok. I'm I wrong for thinking it was a B B gun. Some people. Everything else is fine on him. It's in his leg. I know he needs a vet. I'm trying to find him.