1879 Argentine Rolling Block

[dmboct19]

I am getting ready to load some rounds for my RB and did a chamber cast and was amazed at how long the throat is on my rifles chamber, if I were to try and load the bullet close to the lands it would probably fall out of the case, any one else come across this with these rifles?

[fouronesix]

Yep, common to many if not most old original BP cartridge chambers. I got tired of messing around with conventional BP loads and all the "free conventional wisdom and absolute truths" for types of loads and bullets (including paper patching) with my M1879 Rem RB. I designed and ordered a Mountain Mold to the specs I knew usually works in these type guns and presto! It's now shoots right up there with other big single shots for accuracy.

[ascast]

I had one once, same deal, very common really. I used the Lyman 439186, hard for smokeless and soft for black. It was a fine shooter.
Bullet seated to depth that " looked about right". Traded it off for a car, regretably.

[dmboct19]

Would you be willing to share what bullets work well in these rifles?

[Nobade]

Mine shoots the Rapine 439380, it looks about like the Lyman boolit. I paper patch it up to .442" and load it over a grease cookie and a whole bunch of FFg. Shoots quite well. I made a slick sided pushout type mould before I got the Rapine, it is similar and also shoots well but the two piece Rapine is a lot easier to use so I have gone to using just it.

-Nobade

[fouronesix]

I think, judging by what others report, the bore specs (and likely the chamber throat) varied quite a bit in the Rem 43 Spanish rifles. The bore on my rifle is excellent. The groove diameter is .441 +/- .0005.

The Mountain Molds bullet I designed is a conventional 4 grease groove bullet (3 normal plus 1 for the groove formed in front of the gas check), gas checked, 380 gr., with a standard tangent ogive nose that is about 1 caliber long (about .42" ahead of the tapered front drive band) with small meplat. I use a fairly soft alloy, sized to .4425 and lubed with a soft lube. My normal load is mild smokeless- 21 gr. 5744 with low density dacron filler for an ave. velocity of 1150 fps. Accuracy is excellent.

If interested, added a pic of the MM bullet I shoot in my 43 Spanish Rem RB.

[dmboct19]

Thank you very much for all the information, I really appreciate it thanks again!

[John Boy]

dmboct ... Welcome to the Forum. In addition it's a breath of fresh air to read posts like yours - not demanding, don't ask and never hear from the poster and most importantly ... for being provided with the answer(s) to your post, has the courtesy to say Thank You. :drinks: