If the .410 and larger caliber NE cartridges were being designed today

for the first time, what brass length would be used, how thick would the

rims be? I am asking for answers based on using modern components like North

Fork and G S Custom bullets which seen to cause lower pressures, and modern

powders with their own specific characteristics. Now of course we want to

avoid the need for "filler", we want our 2150 FPS bullet velocity and we want

"low" pressure for our break open rifles. Surely rim and base DIAMETERS would

be affected by bullet diameter to some degree, so I am NOT asking about that.

My question is basically one of physics. My guess is the rim thickness would

be .060 ala the "newish" 500/416 and length would be 3 inches. Remember this

question is based on the idea that they are all new cartridges, so what would

the computers tell us is best based on all the "MATH"?

Good question even the new rounds are based on old cases like the 500-416 and also the big bore bolt rifle rounds are old cases when you consider the 378 and 460 are 416 rigby cases with a belt added.
I would have to say a heavy rim and a good bit less case capacity.

I had a long talk with a friend of mine who is a gun builder in Germany. I wanted him to build a extra set of barrels for my Franz Sodia double rifle and after we kicked it around for a while we decided to make a wildcat based on a .375 flannged case and make it to the specs of a .458 lott or 450 ackley making it a rimmed vertion of ether one of these rounds.

So far we haven't gone forward with this project but first I would want to make sure that the case thickness of the flangged rounds could handel the extra pressure. I don't think you would have to push the pressure so hard that it would be a problem for a double but then again I'm not of the school of thought that pressure is the biggest problem out there for double rifles as long as it's not comeing from a long tappered case ( like most of the old ones are).

As long as good heavy cases could be used I don't think there would be any extraction problems ether. I'll certainly report back if I ever go ahead with the project but I most likely will just have him build a set of .470 barrels for it since he measured the action and they will fit.

I thought by now there'd be some ideas expressed here!?

If the wheel had not been invented until today, would it still be round?



On a more serious note, I think that some cases (.470, .577, .700) would have less capacity so that fillers could be avoided.