Save yourself a lot of grief and money, and rechamber that gun to a 458 Lott and then you can load it to the same balistics of a 450 or about any of the old calibers or at 2350 FPS with a 500 gr. bullet and have a sho nuff real gun...and you can buy brass and bullets and factory loaded ammo...Why would you do otherwise?

I really wanted a 450-400 or 404 in a NO. 1 but I found a 416 Rem which does the same thing plus a lot more, so I got it and that was a decision I have not regretted....