Weatherby Select, 7MM Weatherby Magnum, 154 Grain, Hornady InterLock, 20 Round Box H7MM154IL Ultra-high velocity, magnum ammunition is how Roy Weatherby got started in the 1940s. Today, those same performance qualities are every bit a part of Weatherby cartridges. When combined with a Weatherby rifle, Nothing Shoots Flatter, Hits Harder or Is More Accurate.