+1 on the Sportster, and it comes with a Bull barrel for that price. Or, as Ron M. said, the Savage would be a great choice. Before I decided to go with the H&R, I looked at a Savage with accutrigger and bull barrel in stainless steel for $330 at my LGS. From what I have seen on rimfirecentral and .17hmr.net, few people have been very happy with the Mossberg.buy an H&R sportster for 140$ and have twice the rifle for half the price.
SW