That front sight is very difficult, but not impossible to remove. It is shrunk in place. The way to do it is clamp the sight ramp in a milling machine vise, supporting the rifle on padded blocks. Have one person hit the band under the barrel with a hard, hot flame from an acetyline torch. You want to heat the band red hot as fast as possible without heating up the barrel. As soon as it's hot, hold a chunk of wood against the end of the barrel and whack it as hard as you can with a big, heavy hammer. Make sure the torch guy catches the rifle. If you did it right, it'll pop right off. If not you'll have to cool the whole works and try again. They are not blued under the band, and the barrel will have to be polished out there and reblued. It is not something I try to do if I don't have to, but sometimes it's needed.