Congrats Patrick ...

[villiers]

(Have just received my new BDMP mag) ... for your BP second place. Wish I could get the Werder to shoot accurately.

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[Patrick Chadwick]

Thanks Patrick - now guess - which one's me in the photo?

Wish I could get the Werder to shoot accurately.

Well how are you doing at the moment? With the short barrel and sight radius, you can be happy if all shots are in the black at 100 meters, and really pleased if you get all in the 8 (or a group of equivalent size).

[villiers]

Thanks Patrick - now guess - which one's me in the photo?



Well how are you doing at the moment? With the short barrel and sight radius, you can be happy if all shots are in the black at 100 meters, and really pleased if you get all in the 8 (or a group of equivalent size).

True! I tried guessing ... but gave up. Which one are you?
And then I saw that you had (successfully) taken part in another event. ( At first, I only looked for the metal cartridge event). Don´t even know exactly which part of West Germany Hessen is.

If only ... I can´t even get it to stay reliably on the large target at fifty metres. For the life of me, I can´t make out why. It´s more or less ok at 25 metres with the new "Perlkorn" that fits the front dovetail perfectly.

[Patrick Chadwick]

True! I tried guessing ... but gave up. Which one are you?

A clue: Look at the rifles!

I can´t even get it to stay reliably on the large target at fifty metres.

You do not seem to have mentioned whether those shot holes that are on the target are round or show signs of keyholing. That information (or even a photo) would be helpful.

In any case, it sounds like a real problem, obviously far more than mere PWF. In my experience, one or more of the following faults must be present. I apologize for mentioning aspects which you must surely have checked, but even if the cause cannot be reduced to one item, maybe there is a combination of marginal factors. And other readers may be interested in a full itemization. So please recheck all these:

1) The muzzle crown.
Is it a) undamaged and b) symmetrical? An apparently undamaged crown may still be faulty if it is worn more on one side. This is a common fault on old service rifles maltreated through decades of enthusiastic use of the pull-through (or the dreaded aluminium chain - aluminium oxide being a very effective abrasive).

2) The bore at the muzzle.
Is it bellmouthed? The best way to tell this is to drive a soft lead bullet right through the bore from the breech end. Clamp the barrel in a vertical orientation and oil it lightly. Take a well-greased bullet and drive it through from the chamber end. Use a meter length of 8-10mm brass rod and "bounce" it on the bullet to drive it through. Do not use a hammer! If the bullet starts to fall free before it reaches the muzzle, you have at least found one contributing factor.

3) The throat.
On BP rifles this is unlikely to be shot out, but it may be severely corroded. Nothing you can do apart from cleaning and using a bullet with the longest possible cylindrical section, compatible with the twist.

4) Bullet length.
Use the Greenhill formula - works excellently for BP rifles - to determine the maximum length that could be stabilized. Use the method that I have already described in the Argentino Rolling Block saga to determine the maximum possible cartridge OAL. Make sure that at least 1 caliber of bullet length is in the neck of the case, to ensure adequate pressure build-up and neck expansion before the bullet leaves the case. In the real world, you will probably have to make a length/seating depth compromise.

5) The bullet material.
Should be a tin-lead alloy with something like 3-5 % tin. Too soft, and (depending on the powder charge) the rifling will strip the bullet instead of forcing it into the grooves. Too hard, and it may not obturate properly to fill the grooves (if the bullet is slightly undersized). Which leads us to ...

6) Bullet diameter.
You will often see recommendations to use bullets that are the same size as the groove or even 1 thou or so oversized. Returning to the real world from this theory, if you have slugged the bore properly, you may well find that a) you do not have a mold for the exact size, and b) if you did have such a mold, the bullet, when seated in the case, would expand the neck so much that the cartridge could not be chambered. That is the situation, for instance, with The Mahdi, my Egyptian Rolling Block. Bores usually wear much more than chambers, making the "one thou over groove diameter" bullet impossible to use with many worn bores.

The practical optimum bullet diameter is that which is held by the unresized neck of a clean, fired case. For a BPCR using soft lead bullets it is sufficient if the bullet is a firm push fit in the neck. In this case (unavoidable pun) you will never have to size the cases at all after the first firing. They will last for years (and thinking what they cost, they d..n well have to!). In fact, this is the kind of setup that benchrest shooters aim for! An added touch is always to insert the cases into the chamber with the same orientation.

Measure this optimum (for the case!) diameter. It is the maximum diameter that you can use - anything more will result in a jam! And it is highly unlikely that it corresponds to the slugged groove diameter. If it does, you are very fortunate!
It is probably somewhat less.

- Why is why one uses soft(ish) tin-lead bullets!
So that they can slug up to fill the rifling!!!
Anything with antimony is likely to be far too hard.

KISS - just try 3% and 5% tin-lead alloys, and use whichever produces better results. And use pure (enough) lead. I use offcuts of lead flashing (roofing lead) acquired from the local scrap merchant. Do not use wheel weights, old batteries etc. The various additives and impurities in this type of scrap make the hardness somewhat unpredictable.

Being a KISS fan, I just add 5% or 8% of eutectic (electronics) solder to the lead. As this has 63-64% tin, the result is near enough to the 3 or 5% for my puroposes, and I can't be bothered to work it out to the nth decimal place. It is the consistency that matters, not a theoretical metallurgical calculation.

7) Lubrication.
You will have read about bore-riding bullets. But after the first shot with a BPCR rifle - especially in military rules competitions where you are not allowed to clean between shots - you actually have crud-riding bullets. Even if you do clean between shots, you will hardly achieve a "clean, dry" bore if you want to finish the target on the same afternoon! And if that crud is too hard, the POI of successive shots will get worse and worse and it will soon be difficult to chamber the cartridges. The crud MUST be kept soft. The "shout" is intentional - the bullet rides on the soft crud, and lubrication in the sense of a machine bearing is not what is needed. The grease grooves on the bullet are certainly inadequate when using a full-size Mauser or Werder case, and will probably still be inadequate for the reduced charge of the carbine case.

Determining the amount of lubrication and the powder charge has been described in detail and I am getting a bit tired. So one last point:

For the benefit of any BPCR beginners out there: BP residues are dissolved by water, not oil. The various greases, patent recipes and "snake oils" described in the blackpowder literature all have one major purpose: to provide some water. So you can use an aqueous cream, like Nivea, if it takes your fancy. Someone even once recommended pudding jelly swiped from the kitchen! Just do not use any mineral oils

[jmoore]

As to keeping the crud soft, many BPCR (metallic silhouette) shooters in the US use flexible tubes that they insert into the bore and blow through to soften the fouling with the moisture from their breath. Also works with muzzleloaders from personal experience.

Congratulations on the good showing in the competitions!

As to the Werder, any way of recovering a fired bullet or three? (water or even wet newsprint trap? Even dug out of a soft dirt backstop?)

[villiers]

That s a good idea! Will have to think up some arrangement ... maybe a wet `phone book. There´s no keyholing, the muzzle is ok and the bore is almost mirror (no sign of damage from overzealous cleaning at the muzzle end). The best German manufacturer (Hensel) made the mould according to front and back cerrosafe castings. And the chamber limits the COAL. Over approx. 47mm, the tip of the bullet comes up against the lands. I have noticed that at 100 metres (and especially at 50 metres) there´s splatter around the bullet hole on the paper target (I take it to be grease). I use a bore snake after about every 15 rounds and I ALWAYS blow down the barrel from the chamber end after every round. The lack of accuracy could be partly caused by the front barrel screw that attaches the muzzle protector (I´ve noticed that some old cav. carbines have been altered to make them free floating.

Patrick, the pic is too small and I can´t make out the rifles. You´ll have to come up with some excuse as to which of the not altogether prepossessing individuals you choose to be identified with.

[Patrick Chadwick]

You´ll have to come up with some excuse as to which of the not altogether prepossessing individuals you choose to be identified with.

Well if you put it like that - I must be the handsome one!

I said the clue was in the rifles. There is only one British rifle in that photo, and I'm holding it.

[Patrick Chadwick]

I have noticed that at 100 metres (and especially at 50 metres) there´s splatter around the bullet hole on the paper target (I take it to be grease).

That's fine. It shows that you have more than enough grease in the cartridge to provide lubrication all the way to the muzzle. There should be a slight star-bust of grease on the muzzle face.

The lack of accuracy could be partly caused by the front barrel screw that attaches the muzzle protector (I´ve noticed that some old cav. carbines have been altered to make them free floating.

That's an interesting observation. I had something similar with my Winchester 94 in 32-40. The cap screw at the front of the magazine tube was jamming against the barrel (there is a slight recess for the end of the screw) thus forcing the tube away from the barrel and jamming in the ring. I filed just enough off the end of the screw to prevent this. The magazine tube should be free to move a little in the longitudinal direction, as if it is jammed the POI moves as the barrel warms up. The muzzle protector on the Werder carbine may be having a similar effect, effectively jamming the barrel against the fore-end. Try taking the protector right off and shooting another group. If the group is better, or in another place, then you have found at least a partial cause.

[villiers]

Ok ... will try that.


Attachment 39290



Now, you tell me ...

[Patrick Chadwick]

It shows that you have more than enough grease in the cartridge to provide lubrication all the way to the muzzle. There should be a slight star-bust of grease on the muzzle face.

I think this is one reason why BP rifles can often perform satisfactorily with defects in the rifling that would make a modern rifle useless. The lands at the muzzle of The Mahdi are way down, so that for the last few inches the bullet is just being guided on a straight line by the grooves. But it still works, because if you have enough grease, the bullet is being driven on a hydraulic seal all the way to the muzzle, and an effect such as gas cutting or blow-by just does not arise.

The other factor is, of course, that after that first "clean-bore" shot, rust pits have been filled with crud! And the 11mm generation of BPCRs usually had very generous rifling, enabling them to caryy on shooting with a muck level that would turn my Long Range Sharps into a smoothbore.