I've done this with 30/06 and 35 Whelen, but as the base of the 30/06 is .470" and the 8x63 is .488", you get a "bulge" above the web. I have yet to try 9.3x62, which is a better candidate, as its base is .476", the body is "fatter", and the shoulder is darn near exactly where it needs to be.<br /><br />It "works" in the sense that I have put one 30/06 case through five full-house reloads, and there are no signs of case head separation, but I remain concerned about the practice. I have not heard of any wildcats that follow this practice, but am aware that 9.3x62 is commonly made from 30/06, so there is some room for stretch above the web, but the question is "how much"? Is .018" (~4%) too much?

I would take 9,3x64 rws brass, think it is around .494 on the base. reduce base dia. on the lathe, aneal and form, it will give a perfect case. have you a swedish mauser rifle in this rare caliber?

you are rigth the 9,3x64 have a thicker base than I remeber but it is a possibilty when you have a lathe. reduse the base dia in a flanged way and resize it with a push through die. when rws brass is available like here its not so expensive like 10,75 brass and it will have a better brass quality like this bertram stuff. but if you have surplus ammo its simple. I think it have 5,5mm berdan primer, get some from krautland. I make most of my reloads in 308 and 8x57is with military brass, its so cheap like the berdan primers.

when starting reloading I have rework french 8x50R lebel brass from 1930 for boxer primer. the old big berdan primer fits very strong ion his whole. drill boxer primer wholes for the small rifle primer, its 4,5mm dia.
make a try with your brass, maybe it will work

allways aneal old brass