Man I seen a deer killed by 6 shot at 30 feet. You can never ever say how a shot will effect anything until it is shot.
I use 00 buck in a 3 in mag cause I got a large amount for real cheap like 30 years ago

only shot 10 or so shells so far, got a couple hundred.
I also read where a man was shot in the belly by his kids son, he lived but isnt the same.
One pellet in the heart is all it tqakes to die. A bb gun can kill you and I have proof of that many times over. Dont play with these things, just cause it has 7 shot dont make it worthless, it can and will kill ya.
Some day I will tell about the guy shot himself in his eye with a bb gun, I saw the whole thing.....