I just ordered 50 rnds each of .650 roundball slugs from SGammo by Nobelsport and Centurion, has anyone used this type of ammo before? I will be testing these as soon as they come in to see how well they group at distance and penetrating different materials. A .650 caliber slug @1400 fps should generate some serious blunt force trauma to whatever it impacts, any feedback from anyone who have used this slug would be fantastic.