Thinking about have 1 or 2 RB rifle barrels sleeved...

[glindes]

I have a RB carbine (20.5" barrel ) and a RB rifle (~35" barrel) That I would like to shoot. They are both 43 Spanish or 43 Mauser I believe...I have one loaded cartridge. My chamber casting didn't go well... I'm thinking of 45-70 probably the carbine first. What were other common (easy for me to reload) US calibers these RB were chambered for? RSVP Options please... Maybe just wall-hangers again... Geoff in DE

[Dick Hosmer]

.45-70 is hard to beat, but might be a little hurtful in the carbine. Many BPCR silhouette shooters seem to like the .40-65.

But, since authenticity won't be an issue, you could go for almost anything, even - especially for the carbine - .44-40, or .45LC.

[11mm]

I have a RB carbine (20.5" barrel ) and a RB rifle (~35" barrel) That I would like to shoot. They are both 43 Spanish or 43 Mauser I believe...I have one loaded cartridge. My chamber casting didn't go well... I'm thinking of 45-70 probably the carbine first. What were other common (easy for me to reload) US calibers these RB were chambered for? RSVP Options please... Maybe just wall-hangers again... Geoff in DE

I would be very surprised if either were in .43 (11mm) Mauser. 43 Spanish is probable, and the rifles are fairly common, unless yours has desirable government markings from some country. The carbines are less common, and as Dick points out, a carbine converted to 45/70 would be a handful...or shoulder full. If it were up to me, I would convert the rifle if it is not a truly collectible one. If it is collectible, you could probably sell it and get a good start on something in 45/70. Unless you are a gunsmith or machinist, it's going to cost money to convert these rifles. You would also be thinning out the walls on the original barrel to re-rifle the barrel to 45/70 from 11mm, though that may not matter at 45/70 black powder pressures.
If the rifle is a US built Remington, and you still want to convert it, you could simply have a new barrel screwed into it. Then there will be some extractor work to be done for the new cartridge, because the 43 Spanish rim is approx. .025" larger than that of the 45/70, measured on commercial brass.
If the bores are in good condition and you reload, it may be cheaper and less trouble to get some brass and dies and go with the Spanish cartridge.

[John Sukey]

43 Spanish can be made from .348 Winchester or you can go to www.buffaloarms.com. They have both the brass and the bullets

[jon_norstog]

Most of the Argentine "carbines" were cut down from rifles when Peron had all the old RRB weapons refurbed. My brothers and I have been shooting those guns since we were teenagers. Gotta say, the .43 Spanish is a great round, better than the 45-70 IMO because of the bottleneck shape. easier to extract under stressful conditions.

If you want a 45-70, I would go with a new barrel. The cost of reboring the old bbl and lining the chamber couldn't be much less than just getting a new tube. What I did. Roy Bedeaux in Albuquerque had a .45 blank with whitworth-style rifling, and I had him cut me a bbl that matched the profile of the old Argy barrels - that cute little octagon section before it goes to round. It cost me less than $300 and was way nicer than a patchwork job.

Other calibers we have used in the #1 RB action include .44 mag (my dad) and .444 Marlin (my brother). I would stick with a BP caliber myself. If Roy hadn't had that .45 blank I would probably have gone with the 40-65.

Good luck to you!

jn