Well, I have something like it, a full-length 358-404 improved.
I've easily gotten 2900fps with a 280g Swift. I ran a little over 2925 before I chickened out. My target was 2800 at lower pressure than the STA would do. It looks like it'll push a 250g around 3200, but I haven't done enough to know. This w/e, I'm playing around with ways to make it push a 300 LRN only 1800fps, or whatever it needs to not lead. Will likely get a sizer and see what paper patches will do. Should be able to find an easy 2200 fps with a light charge.
There's another fellow around, Roge Bartsche (sp? sorry) with a for-all-intents similar 'cat. Maybe he'll chime in. He's done a lot more loading for his than I with mine.
Bottom line, it'll kill anything you like, but it's a bit too small for some officials in Africa, and it's overkill for anything smaller than elk over here (though that can be said for the entire RUM line, as well as some WinMags and most Whetherbys, so don't let that stop you!)
Swift's 250 and 280g A-Frame, Barnes' 250g X, North Fork's 250 and 270g, Nosler's 250g Partition, all good bullets at these speeds. I think eventually I'll look around for a 220g high-BC bullet, see how the ballistics work out, as a "varmint" load.
Good fun.
