Reloading metallic cartridges

[villiers]

Just think what an investment the ammunition AND the rifle would have been if you´d kept them!

[Patrick Chadwick]

Many of the M71/84 rifles were effectively unused. By the time they reached the depots in quantity, smokeless powder had been introduced by the French in the Mle 1886 Lebel, and everybody was racing to produce a smokeless powder cartridge rifle with a smaller bore. Like, for instance, the 8mm Kropatschek, which was basically a derivation of the M71/84. So the M71/84 was instantly obsolescent.

As to paper-patched bullets: there are two disadvantages that are mentioned among BPCR shooters.
1) There appear to have been cases of paper stripping off in the bore, leading to ringing of the barrel when the next shot was fired through the stuck paper. Sorry, I cannot quote sources at the moment, so you are entitled to treat this as hearsay.
2) The paper has a slight scouring effect on the bore. A friend who is a top competition shooter in his country has a rifle that has noticeably lost performance because of this. I have no interest in wearing out rifles that are active antiques, so I only use grease-groove lead bullets with about 5% tin. As was shown by Henry Pope, you will not cause any measurable wear in a long shooting lifetime by firing propery lubricated soft/medium-hard lead bullets in a BPCR. After the first shot, the GG-bullets are riding on the lubricant, not bare metal. Just don't use recycled wheelweights!

And, of course, the original M71 or M71/84 cartridges in their boxes are far too valuable to be shot!


Patrick

[villiers]

Just to complete my education:
Is it worthwhile getting a lube/sizer? The bullets from a sizer seem to look quite a bit better. At present, I lube by hand and am over-liberal with piling on the grease. Using this method, the bore stays clean for a lot longer than with the precisely lubed and sized pre-loaded commercial M71 rounds I initially purchased.

And, at present, I haven´t added tin to the lead. Should I? (Why? What does it do?)

Patrick

[Johnny Peppers]

Just think what an investment the ammunition AND the rifle would have been if you´d kept them!

I was in college at the time, and was lucky to get a rifle and a few hundred rounds of ammunition.

As to paper patch slugs wearing out a bore, I called my friend on that one and he said his favorite Shiloh Sharps in .44-77 Sharps had over 2500 PP rounds through it with no loss in accuracy.

[Patrick Chadwick]

Just to complete my education:

I’ll do my best, but there are several interacting factors, so no easy yes/no answers.

Is it worthwhile getting a lube/sizer? The bullets from a sizer seem to look quite a bit better.

They do indeed. But I once managed to make the German national championships for muzzle loaders with as-cast bullets. Muzzle-loader bullets MUST bump up (technical term: obturate) enough to fill the bore, so sizing is not a must. What is vital is that the bullets obturate sufficiently to fill the bore.
However, if you want a precise fit to bore diameter from the outset, as may be the case in a BPCR, then sizing is useful to adjust a slightly oversized bullet to suit, and saves buying yet more expensive custom-molds. Yet I managed a second at 300 meters in the BDMP (national) using a 45-70 Sharps with slightly undersized bullets (about .456 rather then .458), relying on the obturation to fill the missing 0.002”. The trick is to have the right bullet hardness – see below. In this case, I used an approx. 3% tin content, simply achieved by adding 5% of eutectic solder to the lead.

At present, I lube by hand and am over-liberal with piling on the grease. Using this method, the bore stays clean for a lot longer than with the precisely lubed and sized pre-loaded commercial M71 rounds I initially purchased.

A bit too much lube is definitely better than too little. You will read quite often of "bore-riding" bullet forms. But once you have fired the first shot in a clean bore, in a military competition where you are not allowed to clean between shots, then all subsequent shots are, in fact, "crud-riding". I.e. the lead hardly touches the bore, except on the edges of the lands. Sufficient lubricant is vital, otherwise the crud becomes baked harder and harder with each succeeding shot. The grooves fill up and accuracy goes to pot. A well-lubricated BPCR or muzzle-loader will show a light “star” of lube around the muzzle.

And, at present, I haven´t added tin to the lead. Should I? (Why? What does it do?) Patrick

Basically, yes, you should add tin. How much depends on the load, or rather its effect in terms of breech and muzzle pressure. And the precise relationship of the bullet diameter to the land and groove diameters.

A rough guide – you will have to experiment with your own rifle!
Pure lead, Brinell hardness 5, used for muzzle loaders and Minie rifles (bullet diameter less than land diameter) obturates wonderfully. BUT with a heavy charge this can lead to “blowing the skirts” off Minies with a recessed base as they exit the muzzle, which ruins accuracy OR to bullets being stripped by the rifling, which means you are effectively shooting conicals in a smooth-bore, and results are worse than if you had stuck to patched round balls!
So: add about 2% tin (i.e. 3% of the eutectic solder). This raises the hardness to about BH 8, and appears to allow adequate obturation while avoiding skirt-blowing or stripping.
3% tin, as mentioned above, produces about BH 9, and seems appropriate for BPCR bullets that are larger than the land diameter, but smaller than the groove diameter, as they still allow enough obturation.
5% tin/8% solder (BH about 10) is a hardness that is appropriate if you have groove-diameter bullets in a BPCR. Now that I have the right mold (0.446” as cast), I use it for my M1871, and it ought to work for your M1871 carbine as well. It got me a second in France.
But note that the Tin/BH relationship is strongly non-linear. You have to have about 15% tin to raise the hardness to BH 12. This is very expensive, which is why above 5% tin one usually uses alloys that contain some antimony. The Lyman “Cast Bullet Manual” has advice on this. But note that these alloys are for use with smokeless powders. Harder bullets permit less obturation and require a more accurate match to the bore. For BPCRs the 5% tin mix is about as hard as you need.

But in spite of all this explanation, you will still have to experiment a bit yourself. I suggest you try a 3% and a 5% tin mix, and see which set of bullets performs better. As they say, “your mileage may vary”.


Patrick

[villiers]

Have ordered the tin. Both the Werder and the M`71 moulds were custom made by Hensel from Cerrosafe castings so don´t really want to size the bullets. I´ll never be much of a competition winner and neither will the two short carbines. It´s just a matter of achieving the optimum with what I´ve got. Just as the weather´s got slightly better, The Wannsee range is now closed for maintenance. So I´ll get rid of the last twenty soft lead bullets on Monday and then see what the tin/lead compound does.

[gsimmons]

What's nice about the lube/size is you knock off the high spots and lube the bullet at time. It makes a more precise bullet.

[villiers]

That´s what I thought. BUT: if the mould is made to fit a Cerrosafe casting of the barrel, wouldn´t the sizer die then make the bullet LESS precise?

[gsimmons]

Not with the right size die. The sizer is going to flatten or smooth out the seam on the bullet from the mould on make the baring surfaces on the bullet smoother.

[Patrick Chadwick]

Both the Werder and the M`71 moulds were custom made by Hensel from Cerrosafe castings so don´t really want to size the bullets.

I also use Hensel molds. If you gave Hensel the slugged bore diameter of the rifle in which the bullets are to used, before he cut the mold, the bullets will not need sizing. With added tin, the bullets will probably come out a gnat's whisker larger, as a tin-lead mix fills thé mold better.