I haven't been successful calling Maine coyotes, but caught several in the blueberry fields, both out back and near our house, dispatching them with either .223 or .17HMR cal. rifles, though don't seek them out, armed with only a .17 HMR rifle. The .223 has dispatched coyotes with one-shot at ranges out to 200 yards and is the rifle I carry often to dispatch several kinds of varmints, even out to 250+ yards. However, if I see a varmint beyond that distance, especially behind the house, I'd probably pick a .243 for the shot. I really like 85-90 grain bullets in .243 Win. handloads. They're very accurate!