That AH press release said it's basically a necked down and blown out, and shortened 404 Jeffrey case...which makes it a kissin cousin to the Dakota line and you might say kin to the cases formed off the 375 Ruger case, too.
There are very minor dimensional differences in all these cases.The Dakota cases have a .545 head size because that's what Don Allen thought worked best with the full length extractor and CRF of the Dakota 76 when he developed the Dakota lineup.
The Ruger case is .532 so will fit the standard magnum bolt face. In the end, there is not going to be a whole lot of difference between any of these cases in terms of capacity and velocity.
In terms of velocities etc etc you will get from this new cartridge about what you would get if you wildcatted a 7mmLRM,or 7mm Dakota.It was not hard to figure what this case was going to be because it had to fit a 30/06 length action, so the only way to get more capacity to make it materially faster than a belted 264 Win Mag was make it fatter; which is exactly what the Dakota basic case, and the Ruger, are all about.
Last edited by BobinNH; 01/18/14.
