I was kicking around cartridge ideas for a rolling block project and thought of the blown out 45-70. I know few people have blown out a 45-70 to 475 and named it after themselves. I was thinking a 45-90 expanded to 475 would make a nice black powder cartridge.

Probably not going to go that route, but I was wondering if anyone knew offhand if there is/was an original cartridge like that? (I don't have easy access to Ken Howell's big blue book anymore)

not that I am aware of.. the use pretty much did 45 and 50 calibers, as "small bore rounds" in the BP days

jeffe

CAS, if I understand what you are saying...maybe I don't...blow out a .45-70 case? I'm sorta of the impression they are a straight walled case to start out with...sorta kinda. Maybe you could work something out with the .50-90...necked down a bit?

I got me a 'big blue book', will investigate and get back to ya on this.

CAS, a review of that caliber range in Ken's book reveals nothing based on the .45-70 case in the caliber you are interested in. Cartridges of the World does list the Linebaugh. Thing I noticed in the dimensional specs for the .45-70 is that yes, you can probably do this, but it will be practically devoid of taper in the case...and perhaps a bit odd when it comes to extraction. Just a thought, it you want to explore variations of a theme, the old British BPE cases tend to have a LOT of room to grow, and they seem endless in variety. Getting brass may be problematic...maybe back to the .50 basic for your speculation???

Cas,

Sounds like you may have found one of the rare combinations of neck up/down combinations that have yet to be tried. As you mention, the 45-70 has been opened up to .475", Gary reeders 475, as well as the shorter versions, 1.6" 475 Linebaugh long, 1.4" 475 linebaugh and 1.275" 480 Ruger.

Sounds kinda like a 470 NE short. What were you thinking of housing it in?

JD Jones 475JDJ is one as well, ever so slightly different in length than the Reeder.

I was looking into a re-barrel Carl Gustaf rolling block. The extractor for the 8x58R would work for the 45-70/90 cases without any extra fu$$.