As Bronko mentioned, keep a bore light with you. Another thing that can help in keeping you from getting a bum barrel is to keep arange rod with assorted size jags and a samll bottle of oil. run a lightly oiled patch down the bore. you should be able to feel any rough spots in the bore. If everything feels smooth and normal from muzzel to breach, the barrel is probably ok. This is also a good way to check for "walnuts" caused by shooting a rifle with a short started bullet. That will feel like a slick spot at some point down the bore.