To carry on where we left off...Smokeless in a Mauser M1871 or 71/84

[Patrick Chadwick]

Sorry Carl, bad typo, fingers got ahead of the brain again.

I should have written "you are NOT being unhistorical if you do this".

[geberl]

Well, I don't shoot matches with my 71/84's but I've run a few thousand rounds through them and all I've ever used is 5744. I bought two thousand bullets from a guy in Canada before he was put out of business, good bullets. I shot those up then started casting my own, only observation I can speak of is with the bore diameter. My best shooting rifle has the bore marked 10.95, I can get it to group about 8" at 200 yards off a bench. I think it shoots good enough for myself, it definately will outshoot my trapdoors. Maybe I'm just not expecting much but it works for me.

[Patrick Chadwick]

8" at 200 yards is good for a military BPCR. In fact, I would say you could certainly participate in a match and get a respectable score. The problem would most likely be that most matches only permit black powder, and for military rifles you are usually not permitted to clean between shots. That means you have to get experimenting to find how much of what lubricant your rifle needs to get through a match without cleaning! Why not give it a try?

Patrick

[geberl]

Well the only matches in my area I could compete in are service rifle and you can't use a bullet diameter this large. I have been trying to get the club to run a few antique matches but haven't had much interest. On a typical session with a 71/84 I'll shoot anywhere from 40 to 60 cartridges, not sure how you run your matches in Europe but the ones I compete in the States are 50 shots. That is service rifle and you can't clean during any of those either. Of the 71/84's I own the bore diameters vary 11.05 to 10.95 and the larger the bore the less accuracy I've obtained with .446 bullets. My 1888 with a 11.05 bore probably wouldn't hold 18" at 200 yards and the bore is just as nice as the one with a 10.95. The couple 11 marked rifles I have shoot better but not near what 10.95 rifle is capable of doing. I played with alot of 9x57 rifles, really enjoy that calibre, and I've found alot of variation in those bores as well. I ended up having three different diameter bullets manufactured to get them shooting well, I'm assuming the same might be true of the 43 mausers. With the variations in the bores some might need a slightly larger bullet to shoot well, honestly don't know just speculating. I've seen it in the 9x57 so I'm assuming the same would apply in this instance, .001"-.003" in bore diameter would really effect accuracy.

[Patrick Chadwick]

xOf the 71/84's I own the bore diameters vary 11.05 to 10.95 and the larger the bore the less accuracy I've obtained with .446 bullets. My 1888 with a 11.05 bore probably wouldn't hold 18" at 200 yards and the bore is just as nice as the one with a 10.95. The couple 11 marked rifles I have shoot better but not near what 10.95 rifle is capable of doing. I played with alot of 9x57 rifles, really enjoy that calibre, and I've found alot of variation in those bores as well. I ended up having three different diameter bullets manufactured to get them shooting well, I'm assuming the same might be true of the 43 mausers. .

You have achieved a very important insight - accuracy in a BP rifle is just as dependent on a good bullet/bore match as for more modern rifles. Unfortunatey this means that you either have to able to spent a lot on bullets, or get into casting your own. I think I suggested before that paper patching a lead bullet up to size is a simple way of finding out what bullet matches best. By matches I mean the size that produces the best ballistic results.
The CIP (yes, it's covered by CIP) values for the 11.15x60R chambering are: bore diameter 10.95 mm, groove diameter 11.50 mm. Let's assume that the bore/land ratio is 1:1, then the bullet that can neatly be distorted to fill that cross-section is one with a diameter (10.95 + 11.50)x1/2 = 11.225mm or 0.442". Doesn't quite work so simply, as the bullet is not a fluid, and experience shows that about 0.446" is a good first start. But that is for a new bore. If your bore is oversize (no great surprise after 130 years) - you quote 11.05mm - then I would try with a 0.448 bullet with a 5% tin/lead mix.

"So where do I get that?" I hear you ask.

The answer is, from someone who makes custom molds for muzzle loading rifles. Here in Germany, for instance, there are several who, if you give them bore dimensions of your rifle (bore size, land size, bore/land ratio) or, maybe easier, send them a slug that has been driven through your barrel, AND say what lead/tin mix you are using for the bullet alloy, and what bullet weight you need, will make you a mold that drops bullets of the right size that can be used without calibration. So look for such a craftsman in your country. They will exist, but you will have to find them yourself. Ask some muzzleloaders, get a muzzle-loading magazine, or search the net. Don't forget, once the powder has gone bang, then the interior ballistics of a BPCR is much closer to a muzzle-loader than to a modern nitro-powered rifle firing a jacketed bullet.

Aternatively, get a standard mold for a 450 or 451 muzzle-loader from RCBS, Lymen, Lee, etc and an appropriate sizing die. The drawback here is that you would have a hard time sizing down that much, and the grease grooves shrink in the process. The closer you can cast to the final size, the better. In the end, a custom mold that saves sizing makes better sense than buying a standard mold + sizer + extra work.

Good luck with your further researches!

Patrick

[geberl]

I collected mauser commercial arms primarily had a few dozen military examples and one day decided I needed some earlier rifles so I bought M71, M71/84, ect.......but never became too involved with them. On the commerical side of German mauser production it seems a land diameter was never the same. Might have an 8x51, 8x57, or six 8x64's and none of them were the same, the only ones close were the 7x57's. Most of the 7x57's I've owned were close on bore diameters, but all 8mm's and the 9x57's were the worst examples for uniformity. The larger bores I didn't buy in quantity so my samplings were smaller and I didn't notice it much but all the smaller calibers exhibited variation to some extent. I had assumed the 71/84's were the same and noted long ago the markings and had surmised this was the case but never delved too deeply into the 11.15x60r calibre although I enjoy using it. I actually have a long ago converted 71/84 guild sporter that I've used hunting boar. In the states most Americans are used to the uniformity of American Arms and don't realized the inaccuracy of their rifle is due to European manufacturing of the day. I've made some good buys on rifles that "wouldn't shoot well" because the wrong bullet was being used. I've sold most of my collection six or so years ago and just kept some of the ones I enjoyed shooting most. Another calibre I think that is neglected alot in the States but is a very accurate and fun cartrige to shoot is the 8.15x46r. I have two mausers in this calibre that I take out as more often then some rifles but again I've seen quite a bit of land variation in these. I ended up having some custom equipment made for this calibre and feel it was money well spent.

[Patrick Chadwick]

Olson gives the groove depth for the M71 as 0.012", but for the M71/84 he gives 0.006", i.e. half as much. The CIP values I quoted give a groove depth of (11.50 - 10.95)x1/2 = 0.275mm = 0.011" which corresponds to the Olson values for the M71, where you might expect to match the later M71/84, if it was indeed different. So I am not quite sure if Olson was right about the 0.006" for the M71/84. It would be helpful if you could slug all your 71s and 71/84s and give me the results.

The only sure answer is the recommendation made over and over again in the Lyman manuals "Slug your bore and size accordingly".

Those deep grooves have an advantage: if the bore is worn or scratched, there is enough "meat" on the rifling to hone the bore and improve the surface. But they also mean that a medium-to-soft lead (8-12 Brinell) is advisable to get a good obturation of the bullet. A soft bullet will slug up to fit, but a hard bullet may either allow gas blow-by, or create an unecessariy high pressure, depending on its size. Basically, a harder bullet is more critical.

Patrick

[dogtag]

I've never been able to fathom why people buy BP rifles and then shoot them with smokeless.
Half the fun is the smoke and boom, plus the casting and loading.
I clean my 71 right there at the range. One brush, 6 wet patches and a couple of GI bore cleaner patches - presto, it's done.

[Alfred]

I've read that the 40 Caliber BP bottle neck cartridge, 40-80 I think it was, scored better at one thousand yards than modern smokeless powder cartridges up until the 7mm Magnums came along.

The article I read on this said that the Heavy loaded BP cartridges from 45-70 on up had far less deviation in velocity than smokeless powder cartridges, at least in the propellants available up until that article was written, about 1980 or so, maybe earlier.

The .40 bottlenecks were apparently the most efficient as long range target rounds.

I've only loaded BP in .32 S&W shorts so far, for a I J safety hammerless, but have used BP C&B revolvers for near fifty years. The C&B revolver gives up nothing to cartridge guns of the same power class so far as accuracy goes, if you do your part in loading consistently.



PS
How well would a paper patched bullet work in these rifles?

[gunner]

Hi Patrick,

You wrote that you use the SP No.4 for your 1871/84 loads, we want to try it also with BP. Is it possible that you can give me the bullet weight and a powder range where we can try it out? I read your thread " To carry on where we left" , but if i am not blind are there no load datas. I would be happy if you want to help me again. Excuse me for beeing wiry.

Regards

Gunner