It doesn’t happen that often, but when Russell Currier gets hot on the range, there’s not a lot that can stop him. The Maine native is a notoriously fast skier—but also a notoriously inconsistent shooter. Sunday, at the North American Biathlon Championships, he wasn’t exactly on fire—more of a slow burn, perhaps—but the fifteen of twenty targets he hit was just enough to net him a satisfying win in the 15 k mass start race,...