Jorge,
Have you tried cast bullets?

If none available, you could cast your own or pay a company to do so.

Foe similar reasons, I have laid in a good supply of components for my .405 WCF. As you know .411 same as for the 450/400 .

Good luck with finding good bullets.

CRS, NRA Benefactor Life Member, Whittington Center, TSRA, DWWC, DRSS
Android Reloading Ballistics App at http://www.xplat.net/