I managed to build a 458 Win Mag at home out of an old VZ24 that I got from a friend. I'll post some pics of the build along the way when I get a few minutes. Here is a quick shot of the finished product.
http://imageshack.us/a/img43/3219/yqpb.jpg
http://imageshack.us/a/img820/8919/dzvn.jpg