Has anybody tried this round?

http://ammoguide.com/cgi-bin/ai.cgi?sn=VfitAZCIQi&catid=249

Its just the 404 jeffery necked down, and shoulder moved forward. Or, the 416 Dakota without the fireforming.

It dosnt say anything about what ballistics you might get, but, what do you thing, just looking at the case?

Looks like the Dakota "with" fireforming, to me. I'd say it's as good an idea as any of the other 416-404's. Should be an easy 400/2400.

quote:

Should be an easy 400/2400.

or a bit more

Will it need a magnum action like the Rigby case?

Well, with a 2.85" case, you could certainly seat a bullet past 3.6" but not much point in going past 3.7" with a 400g bullet (maybe a Barnes X.)
Point is, you could chamber a 416-404 in a standard long action just fine. One of these guys has a 404-based something (358?) that seats out to 3.7-something, so it can be done. Gives you a little more room if you want it.