Well, if you don't want them to suffer, don't use a .22 lr on them, as only a perfectly placed shot will do the job quickly, and getting them into your comfort zone of 30 yards won't happen consistantly. Get yourself a cheap single shot in the .223, it'll do the job and not break the bank. Or, you could also use a 12 gauge loaded with 3" 4 buck and be very leathal out to 45 yards.