Just my two cents...after you manage to get rid of the critters they will come back. Every time. If the site is attractive to woodchucks one year, it'll look just as good to the new chucks that come around the next year. The solution is a lot of work and some money, but when it's completed you shouldn't have to worry about them anymore. If you have a concrete floor inside your barn then you only have to worry about the outside wall, if it's dirt inside...well, you have a lot more work to do. The solution is burying fencing under the ground flat, just a few inches under the surface. If you can find someone tearing out an old chainlink fence you're good to go. Otherwise, buy some cheaper stuff. Attach the end to the girt boards securely, then bury the rest. A chuck won't go out 4' from the wall to dig. They'll dig right up against a wall, hit the fence and quit. If you have a dirt floor inside, the whole floor will need to be done, tied together and secured to the walls, then covered in gravel or more dirt. It's a lot of work for sure, but does work pretty well, until the woodchucks start carrying snippers....lol. Good luck. Besides that solution, I love my .223...
