nice rifles!
I have a very nice Remington 1879 Argentine 43 Spanish Rolling Block, which of course, is similar to your RB. Had it since the latter 1960s. Take it to the range every once in awhile to lob some of its 370 gr cast bullets downrange. Hoot to shoot and always brings one of fellow shooters at range over to ask about it. Took it a few times deer hunting when I hunted as a teenager, but never saw a deer when I had it with me. Darn it!!!!
LOL, back in the 60s, it was impossible to find 43 Spanish ammo for it. I discovered the 43 mauser ammo for the 1871 German military rifle was very close to the case dimensions of the 43 Spanish and had same diameter bullet. Found some new manufacture smokeless 43 Mauser ammo being made in Canada back then that was correctly loaded for use in the 71 German rifle. Started shooting it back then in my RB. I could then just trim back the longer fire formed 43 Mauser brass and reload it. Actually still use some of the 43 mauser brass I bought back in the late 60s for reloads. Hmmmmm, just remembered, when I got back into shooting my rifles about 5 years ago, still had some of the original 43 mauser ammo left over from the 60s. Decided to shorten its longer brass before firing it and then trimming it back. LOL, thanks to the long neck on the 43 Mauser, able to use a copper tubing cutter tool to trim back the brass on the neck without removing the bullet and etc. Once I had cut the extra brass from neck, easy to remove from bullet.