One thing I never liked about the 8mm RM was that the bullets are seated way down the neck to reduce the O. A. L. Some years ago that led to a discuss with a gun nut buddy of mine that went along the lines that you could use shorter brass, seat the bullets at the base of the neck and get very close to the same fps out of it. Heated discussion leads to a bet. He say you can't get within 300 fps and I say you can.
Only one way to settle that...build the cartridge and build a rifle for it. JGS made me the reamers, Huntington Die Specialties made the dies, and Custom Gun Guild put together a sweat rifle on a 1909 Mauser action and a Fajen laminated stock. Designed the cartridge to shoot 220 Rem Corelokt, which were standard for the 8 mm RM. The new 8mm/350 mag is short enough to work in a standard length action and the velo was within 150 fps of the Rem model with no pressure signs. It shoots <1" groups at 100 all day with R19 and Fed 215 primers.
That become my go to rifle for African plains game for 25 years. I've tried other bullets in it, Nosler 200 Partitions do well with H414, but it absolutely will not shoot any 185s well. Too much freebore on the shorter bullets. Barnes TSX 200s shoot well with R17.
I had been shooting this for more than a dozen years when the 8mm WSM appeared, and is darn near identical in length and capacity. Looks like I was a pioneer, though there is hardly any brass under the sun that isn't necked up and down to every caliber possible as soon as its introduced.
If you have a .300 mag of any sorts, the 8mms don't offer you any big advantage. If you are not a rifle looney, then I'd say the next step up from .30 for hunting is the .338 WM. In my opinion, there is not enough difference between the .338 and the 8mm in the field to worry about.
As for my original bet, the beer tasted good as winning prize, but it was expense in the end.
