Just dropping off some thoughts here...
I have always wondered why - at newer times, at least - they have stuck so much to the already existing cases when making new.
The .375 Ruger is the first really new design in a long time, the Rum's only beeing rebated .404 Jeffery's.

Powders are getting better all the time, so why not make some smaller cases? How many have the use - really - of the RUM's and belted mags?

I would like a case between the 06-family and the belted mags, one that would improove ballistics of the 06's and still give you 4 in the magazine, compared to the belted's 3.

OH, do i - really - need them?

Well, hell no!

Aren't these specs pretty close to the 9.3x64 case?

66 case, newton case and 68 case are good but i get what you are saying...

the answer is either (a) taking the belt off and deepening the extractor groove of the 375 h+h case or lott case and either having a .510" casehead/rim with a bastard rim or a big rebate to .470"

or (b) making an entirely new case that is .490" casehead and doing the rebate to .470" (acceptabli imho but not ideal) or the bastard rim thing

Bent,
the WSM and RUm cases are techincally propitrary cases, as you can NOT make them from 404 jeffe cases and have the same capacity.

the 450 marlin is also a "can't make it from anything" case.


the 470 Mbogo, the 600 OK, the 550 Mag can't be mode from other cases, so to speak, in the case of the 470 and 550mag, the "parent" cases are too short.


As for a case between teh '06 and the belted mags.. that is the 376 steyr....

and between the belted mags and the rums?

the ARs...

leol

the steyr is not long enough for bents liking, am i right?

make it .3" longer and its in buisiness...

since this is a wildcat fantasy thread i say 2.65" case length .490" casehead with a .470" rim.

or just do the .470" rim on a h+h case sans belt.

aint wildcatting fun!

Boom,
The .376 Steyr is just a shortened 9,3x64, case head of .504", but i want it even smaller.
The 10,75x68 is just that, but maybe still to wide to get one extra between the 06's and the belted mags. It is a tad longer than 2.65", has a case head of .489" and a rim of .492 - now, that is pretty close to your specks, ja? But why do you all of a sudden want rebated rims??

I think we have to play some more with that 10,75 round............!
I really hate RWS for discontinuing this round.

oh yeah, forgot to think about the 10.75x68

soooooooo

neck it down to 375 and have a rough 375 h+h case capacity maybe 5% less...

i dont like rebates but i dont like boltface work either.

Toward the end of last year, I started thinking along EXACTLY these lines. It seems to me that the best fit would be a cartridge based off of the 8x68 or 6.5x68 for the smaller bores. The only changes to be made to the basic shape would be slightly less body taper and going to a 25 degree shoulder. The result should feed slick as snot and beat '06 based rounds by 150-200 fps.

Gabe

Well, you could have somebody make it for you. http://www.huelsen-horneber.de/ makes custom brass.