Warning. Do not shoot ANY bullets into the air, even CBs and BBs, in inhabited areas. For flying vermin, use CCI .22 shotshells. Slightly louder, but oh so satisfying for pigeons, crow-like birds and other airborne vermin.
Say, BTW, what's everyone's policy on a fast and painless death for vermin (possums, raccoons)? My record isn't very good. If they wander away wounded, so be it.
Regards,
Ledbetter