I like to sit around and shoot birds with frozen paintballs
Why on earth would you shoot birds?
It's fun and it's more effective than shooting them with real bullets
While it is good to not use real bullets because people will think that you are cruel, it is not good to hurt the birds with paintballs. Those could also hurt and kill a bird which will have people think bad of you.
Stop being sensitive, it's not like killing innocent animals is what I do.
If you are shooting birds when you are killing innocent animals, and you should stop doing that. It's often viewed as pretty cruel.