Bow. ;-) (Seriously, bunnies holding under the brambles with blunts is a hoot).
Though I frequently use a rimfire pistol or rifle. I also pester them with a flintlock shotgun.
One of my best bunnie-guns is a S&W M-14 Target Masterpiece with .38 wadcutters. I used to shot PPC and in the winter it was good sport to head shoot sitting bunnies.
Bookmarks