is there a problem using some other garden instrument? Shovel, Hoe, Machette? It seems to me like killing a fly with a shotgun? Not that I mind shooting snakes, it just seems to me that in a residential area, one would do better to keep the noise down, and not raise any questions of doubt.
I know some kids in my neighboor hood who got in trouble for shooting a bb-gun into thier garage, into a target designed for trapping bb's. The city ordanance prevented them from shooting outdoors. and while the kids were safe, and under supervison of an adult, they were technicaly outside on public proprty shooting into thier garage.
I would not want to risk a phone call to the local PD, and take them away from thier jobs, because my uppity neighboor started freaking out as I was carrying a handgun in my yard, shooting at the ground for no apparent reason.