the last time i used a shotgun for squirrel i used a .410. for rabbits the only thing i've used is a slingshot and a pellet gun .177. head shots are the key. if your looking for rabbits and theres snow on the ground then just follow their footsteps until you come to their hiding hole. usually a brush pile, thick briars etc... With your shotgun in hand kick around and try to flush a rabbit. once you do you gotta be quick..turn the saftey off, aim and fire. fire slightly ahead of it if its running. good luck