Well considering your crazed about Ultra Mags..
I have a funny feeling your gonna be bored pretty quick..
Get a .311 Canadian Imperial Magnum..
It's the very first of the Ultra Line..
Developed in 1989 by a Canadian Gunsmith..
I got one in 1991...
It's a Custumn Sako with 28" Hart Barrel..
It smokes 200gr bullets at 3700 ft/sec..
10yrs before the Ultras and Lazz's came out..
And they are bad bad compared to these...
This gunsmith than tried 30 cal and 7mm cal bullets with similar results.. After a few awesome reports in B.C. Outdoors Mag word caught on, later...
It's a 404 Jeffrey necked to a .311 diameter bullet..
Get Rem to Custumn make one for you on this cal..
You'll be happy.. Won't be disappointed..