A guy at work was telling me he has a custom made muzzle loader that is a 56 caliber (he also said he makes his own lead balls with an RCBS mold) with a 46" progressive twist barrel that takes 400 grains of powder. He said he has killed deer at 700 yards with it. He has a Sharps style sight on it. Now knowing muzzle loaders a lot of this sounds a bit out there, but knowing modern technology anything is possible. He also compaired the ballistics to a 240 Weatherby.

Does anyone know of this type of muzzle loader or if it is possible? I would really like to know.