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Testing loose fitting balls

Discussion in 'Blackpowder' started by Lunie, Jun 15, 2013.

  1. Lunie

    Lunie Well-Known Member

    Folks, I would like to invite opinions, suggestions, and speculation on some testing I intend to do.

    Short version:

    Pietta 1860 Army
    .440" swaged lead roundballs
    ~35 gr of FFFg blackpowder
    Well fitting caps

    I picked up a box of undersized balls to do some testing regarding chainfires. The balls roll in and out of the chambers, and obviously shave no ring of lead whatsoever. Essentially, the interface between the ball and cylinder is all "gap", and should only have 1 theoretical point of contact.

    I have read many folks explaining that they smear gobs of lube over the cylinder face to protect against small gaps that they feel can cause chainfires. Another crowd uses wads underneath the ball. Since I am in the "no lube at all" category, I want to do some testing to improve my own understanding of the subject.

    I am prepared to cause and deal with chainfires under controlled conditions, should they occur. I'm essentially trying to make them occur. :evil:

    If anyone would like to throw out some speculation, observations, or opinions, my flame suit is just back in from the cleaners. Let loose.

    If I get around to doing a "proper" experimental study, I will share the results.
  2. BigG

    BigG Well-Known Member

    No loose balls

    I think the balls have to be tight in order to stay in the chamber under recoil. Mine shave a ring every time.
  3. Patocazador

    Patocazador Well-Known Member

    If you want to purposely cause a chain fire, use the correctly sized ball and cut a slot in one side allowing direct access to the main powder charge. Then sprinkle some powder on the exterior part of the ball.

    I think you're crazy and it will be dangerous but they're your eyes and hands. :eek:
  4. rodwha

    rodwha Well-Known Member

  5. Lunie

    Lunie Well-Known Member

    Yes, that is what the conventional wisdom says... But it wouldn't be an interesting experiment if it did not attempt to challenge a little bit of that conventional wisdom.

    I have the option to do that as well, and I may work with that at some point if I feel the need.

    The short answer is to challenge conventional wisdom, and my own, on the subject.
  6. Patrick R

    Patrick R Well-Known Member

    A few weeks back I was shooting my 1860 Colt Pietta when I ran into a problem while reloading. I tried to put 2 balls into 1 chamber. I ramed it in a little over 1/2 way before I saw my mistake. I had to take off the nipple push them both out with some small dia. brass tubing. I still had 1 chamber ready to fire. When I took the shot flames from the chamber I just unloaded must have had some powder left in it. Flames shot out of both ends of the chamber. I was quickly a bit out of my comfort zone.

    Getting my gun to chain fire, no problem! (At least with no ball in it)
  7. Jim K

    Jim K Well-Known Member

    The trouble is that an artificial chain fire (as Patocazador describes) would not do much toward understanding what causes chain fires under other conditions. I have never experienced a chain fire myself, but I am sure those who say they have did not cut any grooves in the bullets.

    It would be interesting to hear from folks who have had chain fires about what they were able to learn as to the cause. Barring a relic so badly rusted that there were holes between chambers, I have not been able to determine a condition that would reliably cause chain firing.

  8. col.lemat

    col.lemat Well-Known Member

  9. Jim K

    Jim K Well-Known Member

    OK, but which post is balderdash?

  10. J-Bar

    J-Bar Well-Known Member


    How many of those .440 balls do you have?

    I will buy them from you and recast them for my own revolvers and you won't have to risk injury.

    Gimme a good price, Pard.
  11. Lunie

    Lunie Well-Known Member

    Thank you sir, but I'll have to pass.

    I bought the box of 100 with this project specifically in mind.

    Although if I have any left over, I will remember that you offered!
  12. mykeal

    mykeal Well-Known Member

    I am utterly amazed by the fascination some folks have with chain fires. Really - intentionally shooting a revolver with balls so undersized they leave huge gaps?

    All that is necessary (AND sufficient) for a chain fire is for a small, even tiny, leak into the chamber where there is powder and a gas hotter than the ignition temperature of the powder. This isn't rocket science. That leak can be anywhere, at the back from a loose or out of round cap or at the front from a void in a ball that's uncovered by swaging during loading. Sometimes that tiny leak and a very hot gas is all it takes. Sometimes the gas cools enough that it's below the powder ignition temperature and no chain fire occurs even with a huge leak. There's no guarantee that it will happen every time or even 10% of the time, and there's only one guarantee that it won't happen: a complete seal at both the back and front.

    First of all, there's no such thing as a reliable chain fire. You need high temperature gas. There's no control over how that gas flows or how the heat profile is maintained; it's a random event. Having a reliable, repeatable path, like that in a combustion chamber, is what's needed, and you don't have that between the mouth of a revolver chamber and the inside of another chamber. However, assuming the gas gets into the adjacent chamber and is still hot enough, is there a way to get by a round ball that shaved a complete ring? How about this: I've weighed hundreds of round balls, both cast and swaged. I've found lots of them with internal voids (lots more in cast than swaged, but neither is completely immune). All that's necessary is for the swaging process during loading, which peels a ring of lead away from the surface of the ball, to uncover one of those voids, and now you have a gap between the cylinder wall and the ball. A gap is a path for a hot gas to make it's way to the powder behind the ball. All you need is a few molecules at a high enough temperature and you got a chain fire. How often does that happen? Rarely. How often do we have chain fires? Rarely. Oh, and don't forget about the back end: a pinched or wrong sized cap can also allow a leak.
    Last edited: Jun 15, 2013
  13. col.lemat

    col.lemat Well-Known Member

    Darwin award. Go right ahead be my guest.
  14. 4v50 Gary

    4v50 Gary Moderator Staff Member

    The ideal way to conduct such an experiment is with a remote control operated from behind a thick concrete wall and with high speed cameras to capture the chain fire.
  15. 44 Dave

    44 Dave Well-Known Member

    Years ago, when I first got my cased 1860 with brass mold I got to experience chain fires. The mold cast undersize balls.
    You will have the balls coming loose and may even fall out.
    You will have a very smokey mess, but with the powder burning "backwards" there was not as much pressure build up.
    I would skip one chamber, the one that lines up with the loading leaver.
    Do wear eye and ear protection but I never had gloves on.
    You going to do a you tube video?

    I use .44s patched in my .45 squirrel rifle and Kentucky pistol.
  16. Oyvind

    Oyvind Well-Known Member

  17. Lunie

    Lunie Well-Known Member

    My apologies for being a little cryptic, but I would just like to say that my preliminary measurements and testing are producing "expected" results so far.

    Unfortunately, it will probably be a few weeks before I have the chance to continue further. (So if I don't say anything else on the subject for a bit, there is no need to worry too much about my eyes, fingers, etc.)

    Ideally, you all will get some pictures and a write up about what I find.

    In the meantime, please continue with the critiques. Speaking of, why has no one ventured to say that my undersized balls will go rattling down the bore when fired?
  18. Lunie

    Lunie Well-Known Member

    Come on folks, give me a walloping. I know there has to be more in there. :cuss:

    I'm not asking for personal insults. Only critiques of what I am working on, or insults reasonably associated with a critical comment, please. (By that, I mean that you can call me a moron, but I want you to explain why you think what I am working on won't work, or how it could be done better.)

    Thanks. :D
  19. rodwha

    rodwha Well-Known Member

    Do you believe the odds of this happening are minimal from the front? I don't understand the point.
  20. Lunie

    Lunie Well-Known Member

    In a word, "yes", and I think I have an inkling of the reason(s) why.

    I want to test to see if those inklings are valid, or to see if I am wrong.

    If I am wrong, I guess I might have to start doing the ceremonial application of lube to ward off the evil chain-fire spirits, but if I do it will be because I know it is necessary, and not just because of a peculiar tradition or a 1960's mysticism. ;)

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