Same shoulder diameter but shoulder placement is different. I would run a 7mm BC reamer with a 400 pilot to make an easy high pressure 400 Whelen +P
400-7BC AKA 400 BC. 400@ 2150 should be easy now.

https://gundigest.com/gear-amm...tion/7mm-backcountry

400 on down @ 80K PSI is interesting. Shoot heavy bullets fast.

9,3X62 with 286 and 320 grain bullets @ 80K PSI will get you what velocity? 35 Whelen with 250s?

Fascinating is that the extra 20k PSI is absorbed by the case and not the gun. They really need to use this process for 45-70 ammo

might spec the cases to have SMALL primers -- that way, after the first firing, if the gun is intact, you can switch to large primers

quote:

Originally posted by jeffeosso:
might spec the cases to have SMALL primers -- that way, after the first firing, if the gun is intact, you can switch to large primers

I wonder about forming a hard steel alloy from .284 to .411?????

I guess.

But why.

Not like it doesn't kill well now with proper shot placement.

Because green looks greener at a distance

quote:

Originally posted by p dog shooter:
I guess.

But why.

Not like it doesn't kill well now with proper shot placement.

These cases are reloadable. The 400 Whelen is maxing out pressures to get the desired velocities in a standard case so this adds a margin of safety at the same velocity. If you want 400@ 2K fps you will be well below the max PSI. You should be able to shoot a wider variety of 400 grain bullets. Will a brass or copper solid that are longer than lead bullets be able to get the nominal velocities? With the rule of thumb of 3% increase in pressure getting you 1% in performance, the likelihood is good. The extra 20k PSI is being contained by the case itself. The large bore diameter too will have a short pressure curve. On the shorter side, this will make a 308 more comparable to a 30-06 with heavier bullets in theory. Having a .458” shoulder means you don’t have to fuss with making a shoulder on a hardened steel case. I would like to see what this case can do to the venerable 9,3x62 with those heavy for caliber bullets.

I have a hunch that stretching the case that much won't be easy but I like your idea. Uncharted territory though when it comes to the powders and pressures.

Maybe open it up in two or three steps with a fire form for the last one. A rebarrel of a 9,3x62 should be a good donor for the project. A few unknowns for sure but it would make a heck of a great handling gun with old school big bore wallop. Technically it would not be a Whelen with keeping the BC shoulder but it would be in the spirit of the 400 Whelen. It could clean up a 400 Whelen chamber but I’m sure a rebarrel or a rebore of a 9,3 would be more preferred. Now if we can only get Ruger to make a factory load and gun for this they would want to call it the 400 Ruger though a small price to pay for a cool Africa ready gun though.

quote:

Originally posted by boom stick:
Maybe open it up in two or three steps with a fire form for the last one. A rebarrel of a 9,3x62 should be a good donor for the project. A few unknowns for sure but it would make a heck of a great handling gun with old school big bore wallop. Technically it would not be a Whelen with keeping the BC shoulder but it would be in the spirit of the 400 Whelen. It could clean up a 400 Whelen chamber but I’m sure a rebarrel or a rebore of a 9,3 would be more preferred. Now if we can only get Ruger to make a factory load and gun for this they would want to call it the 400 Ruger though a small price to pay for a cool Africa ready gun though.

(sigh)
nix - you don't take a mauser and run it 80k --

Does anyone recall the brass cases of 5 rounds in a neat pack that had a steel base with a brass case threaded into it..claimed 80,000 as safe..I loaded one up back then and loaded it to the hilt and fired it without any problem other than it bothered me and it was expensive, I still have one of those cases in 30-06 somewhere around my shop. It was sold in shops and had some magazine adds best I recall. don't recall if it was reloadable..Doubt if any of you guys are old enough to recall them???Dot recall the name of the manufacturer..

quote:

Originally posted by jeffeosso:

quote:

Originally posted by boom stick:
Maybe open it up in two or three steps with a fire form for the last one. A rebarrel of a 9,3x62 should be a good donor for the project. A few unknowns for sure but it would make a heck of a great handling gun with old school big bore wallop. Technically it would not be a Whelen with keeping the BC shoulder but it would be in the spirit of the 400 Whelen. It could clean up a 400 Whelen chamber but I’m sure a rebarrel or a rebore of a 9,3 would be more preferred. Now if we can only get Ruger to make a factory load and gun for this they would want to call it the 400 Ruger though a small price to pay for a cool Africa ready gun though.

(sigh)
nix - you don't take a mauser and run it 80k --

They are quoted as saying the case takes up the extra 20k PSI so in their theory, it should be fine in any modern rifle capable of 60K PSI loadings