Double check the scope dope or that you used the correct hold over. If there is a descrepancy, fix it and fire a follow up shot. If there is no descrepancy, I would attribute it to the "cold bore shot" and fire a second shot from a warm barrel. If that doest connect, I would go to the range and figure out if it was me or the rifle. Of course only after I was SURE i didnt connect and leave a wounded critter in the woods. I have taken shots in such cold weather from such a cold barrel that I was pretty sure the first shot would NOT connect. Guess what, they didnt. The second ones sure did! I was also positive the situation would allow for a secong shot in case a less than perfect shot occured.