remmington rolling block

i am new here ihope someone can steer me inthe right direction i have a rolling block i think the first model with a bore .454 after slugging it. the cartridge chamber measures rim .651 base of cartridge .556 shoulder .548 neck.476 length 2.26 the bore is realy good and i would like to shoot it if i can find some cartridges

It sounds fairly close to a 45-70, but it's worth it to do a chamber cast out of Cerro-safe to be sure...

the measurements are taken from a chamber casting and its a shoulderd cartridge. the way it looks as if someone has tried to change the chamber and screwed it up. i realy would like to make it into a 45-70 but dont know how as the chamber is already to big for a 45-70 cartridge

I'm sorry - I missed that you mentioned it was a shouldered round. I see that now. My second thought was that it was an 11.7x51 Danish, but that's not right either - it's not shouldered either. I'm checking in several reference books I have and will get back to you if I find it. The closest I've come up with so far is the 44-77, but that was chambered in the No. 3, not the No. 1. Could you have a No. 3?

i just ran across a picture of the rear sight and it said it was from a argentina 1879 maybe that will tell the modle

.43 Spanish. Ammo, brass, and dies are available via the net.

thanks guys i think i have it figgerd out. this is my first rolling block it sure is a neat gun. did the argentine ever come with the saddle ring this has one on it . it was also chrome plated witch i have removed whoever plated it didnt do a very good job the barrel had a lot of uneven surface like it was polished with a flapper sander or something.