You should be fine if you misjudge it by a few yards. I carry a rangefinder with me and will quickly range a few trees if I have time when I set up on a bird. I shot one last year with my .410 Tristar Viper at 38 yards and it didn't even flop, looked like you flipped a kill switch when I squeezed the trigger. I'm using Viper Ammunition, 1oz of #10's.