Westley Richards produced a small number of Droplock Double Rifles in 577 Nitro Express for clients who demanded the maximum stopping power available from a shouldered firearm. These guns weigh approximately 16 pounds and are regulated to fire 750-grain bullets at 2050 fps. The Droplock mechanism's field-serviceability was considered especially important in these extreme-caliber guns, which were used exclusively on elephant and occasionally hippopotamus. Type: Rifle Action: Double / SxS Caliber: 577 Nitro Express Capacity: 2 Year introduced: 1900, United Kingdom Weight: 240 oz Overall length: 44.5" Status: Active Intended use: Dangerous Game