Hi all , i have been reading these forums for a long time , never had a reason to post anything until now .

Anyone have any information on the 475 OKH ?

I have a chance to buy one, it also has dies and some brass and bullets with it .

I have spent a couple hours on line searching , but but cannot find any kind of load info , ballistics , etc on it .

Not even much of the history of it other than it being a O'Neil /Keith/ Hopkins wildcat based on the 375 H&H case . '

Any info , load data, places to look for info , would be very welcome .

PS Not a complete strange to big bores , have owned a 460 Weatherby for about 30 years , and sometimes hunt deer with a 4 bore muzzleloader

thanks

Joe C

Looks like pretty much an orphan. Found one picture (and no ballistics) on Wikipedia. It looks almost like a .458 Lott. If I were you I'd avoid it.

If it is based off the .375 H&H case you might use .470 Capstick data.

As far as ballistics I would load it to .470 NE levels i.e 500 grain bullet at 2150 fps.

A vague memory says this was one of Elmer Keith's brain storms

COTW #16 on p313 says it's virtually the same as the 475 Ackley Magnum pushing a 600gr to a muzzle velocity of c.2250fps with 90 gr of IMR 4320.

The same data is in Donnelly's cartridge conversions which apparently originally comes from Ackley's Handbook Vol. 1 p.503. Straight case based on 375 H&H.

The 475 Barnes Supreme looks like a parallel development with the same 90 gr of IMR 4320 & 2250fps.

Thanks for the info

I was going to try to find it in COTW but couldn't find my copy of it . (have a new on on the way ) .

I know ii is an odd-ball cartridge , that's the reason i am interested in it .

Just something to play around with .
I thought it might work pretty well with cast bullets.

Still open to any and all info i can find

thanks again

Joe