Even with a heavier barrel, there will still probably be a lot of barrel heat up with rapid, successive shooting. It may just take a few more shots for that to happen, as there is more steel to heat up. Either way, you will have to let the barrel sit every few rounds to cool anyway. I would just get the gun with the sporter barrel and not worry about it. I don't think you are going to be shooting so much, that it will heat to the point that any damage will be caused. Just watch the barrel and make sure it doesn't get too hot, and then let it cool for a while, the gophers will be there another day. Maybe take a second rifle like a .22 with you, use the .22-250 for the longer shots, let the gun cool, and take out the closer ones with the .22.