SHOOTING THE BLACK POWDER REVOLVER
c John L. Fuhring 

Number 1 cause of chain firing
A cross section of a revolver chamber showing crushed powder grains caught between the slug and the chamber wall
and forming a powder train.  A discharge from an adjacent chamber will set this burning and result in a chain fire.

     When I was "soldiering" with the Union Cavalry, we would make up and carry paper cartridges (with Cream of Wheat in the front and black powder in the back) because paper pistol cartridges are what was used in the 1860s and it sure made reloading during battle reenactments a lot quicker than loose powder - besides that, powder flasks were forbidden during the reenactments for safety reasons.   I noticed that I never got a chain fire while using cartridges although the only thing between the hot gasses from the fired chamber and the powder in the next chamber over was a layer of compressed Cream of Wheat.   Gee, maybe it was because there were no powder grains getting caught up when loading.  

     When I would carefully observe what was going on during my ordinary reloading process, I noticed that the problem with grains of powder getting entrained is made much worse if lots of sticky ‘Crisco’ or other grease had been glommed on the cylinder during the previous loading.  I will talk more about "mistaken" ideas regarding glomming on Crisco or other stuff in a next article, but for now just let me say that, against all advice, you should not put any substance on top of a cylinder after you have rammed the bullets in.  You read that right, do not put anything on top of the slugs after they have been rammed in their chambers.  Plastering on grease over the slugs after they are rammed in does absolutely no good because, after the first shot, all the remaining grease will be blown away and blown away grease will not prevent chain firing, but more importantly, having all that sticky residue there when you go to reload definitely contributes to sticky conditions that attracts powder grains to stick on places they shouldn't be.  

     With this insight into chain firing, I conducted many experiments to both prevent AND to induce chain firing and I have confirmed this powder train theory to my complete satisfaction.  I'll say this right now --  to prevent the vast majority of chain firings, the top of your cylinder must be very clean of all loose powder grains and you must not entrain any grains between the slug and the chamber wall when you ram home the bullet.  A little later on I will describe my experiments and suggest that you should try those experiments for yourself.

     OK, for the time being, let's just assume I'm right and that clean powder management is as important as I say it is.

     The cleanest way to load a chamber (and the method our ancestors used) is to use preloaded tissue paper cartridges since there is no way for loose powder grains to get between the ball and the sides of the chamber.  You might want to give some serious consideration to this method of preloading your ammunition using cigarette paper tubes because it's clean and reloading is really fast.  Because there are no spent cartridges to eject, reloading is nearly as fast as with a modern revolver.  You can even make up boxes of ammunition complete with a cap attached to each cartridge.  One bit of advice though, the rear of the cartridge (next to the flash hole) should be ruptured with your fingernail before loading, exposing the powder, or you may get a misfire and will have to put on a new cap and try firing it again.  

    Preloaded cigarette paper cartridges are a superior way of loading from many standpoints, but the fact is that most of us don't go to the bother of making them up.  Besides, it is difficult to apply the proper amount of grease when using paper cartridges and I'll say no more here about cartridges, but I would like to invite you to read my article on making paper cartridges if you are interested.  There is a link to that article at the end of this essay, but for now, please continue to read about how most of us load with loose powder.

     Hey, guess what???  I just heard about these 30 grain pellets of Pyrodex that are made for 44/45 caliber revolvers.  They are rather expensive compared to loose powder, but loading with them would be much faster and cleaner.  Using these pellets would eliminate any possibility of spilled powder getting on top of the cylinder and would be just about the cleanest way to load a revolver.  Pyrodex, especially in pellet form, is hard to ignite, so you have to put in the pellets so that their dark, black powder, side is facing the nipples.   By the way, the manufacturer of this product doesn't recommend coating the outside of the cylinder with grease, but does recommend using a wad of some kind.  

     From here on this article is all about how we can prevent chain firing by loading the "conventional" way using loose powder.  A chamber can be successfully loaded from a powder measure (or - heaven forbid -- a flask -- which most of us use), but only if great care is taken to prevent powder from getting on top of the cylinder where it can get caught between the chamber and the bullet .   The important thing is to be absolutely sure the top of the cylinder and the chambers are free from powder grains that can get caught between the chamber wall and the ball as you ram a bullet in.  

    Recently Michael Costa sent me a excellent little device he made from the top of a high power rifle cartridge with the bottom 3/4 sawed off.  The neck of the cartridge sticks down into the chamber and it acts as a funnel for the powder, thereby absolutely preventing any grains of powder from sticking to the upper sides of the chamber when pouring it in.  This is such an easy accessory to make and it works just marvelously, I highly recommend its use especially if you are loading from a powder measure or a flask with a large diameter spout.  I really think that this simple to made device is the most effective device for cleanly loading chambers since paper cartridges were invented and it is an important tool for you to use to prevent chainfiring.  Thanks very much Mike.

     Some years ago, while experimenting with a Colt replica, I made a useful discovery.  After formulating the clean loading procedures mentioned above, the rare chain fire that still occurred entirely disappeared  when I simply removed the sharp edges at the entrance of each chamber.  The following is my understanding of why I stopped having even that rare kind of chain fire.

     As most revolvers come from the Italian factories, the openings of the cylinder chambers are machined with sharp edges.  I noticed that these sharp edges tend to bite into the soft lead of the ball as the ball is started and when the ball (or conical)  is rammed down, the ball is shaved down.  This shaving must leave the slug undersized and, depending on how the bullet first encountered the sharp edge, it would probably be unsymmetrical too thus creating a gap where hot gas from another chamber can enter and ignite the charge.   Bullets not fitting the chamber walls tightly can allow hot gases from a neighboring chamber to ignite the underlying power and again, plastering on a lot of Crisco on top of the loaded cylinder does little good, the charge in the chamber remains vulnerable to a cross fire.

     Backed by the testing I've done, I will say right now that you can improve your revolver's accuracy and eliminate this probable cause of chain firing by using a countersinking tool to remove the sharp edges at the entrances of the chambers.  It is easy to do and only takes a couple of minutes.  Simply hold the cylinder in you left hand and carefully grind with your right hand until the sharp edges of all six chambers are removed.  Apply no more than hand pressure, but keep the alignment straight and take off no more steel than necessary to remove the sharp edges.

     When finished, your cylinder chambers will be lightly ‘chamfered’ and I have found that no more than a very light chamfer is needed.   If you apply the pressure so the countersink is straight on, the chamfer should be acceptably symmetrical without use of any special alignment tools.  I've done this operation on cylinders for several of my pistols and several friend's pistols too and after inspecting the results under a strong magnifying glass, the job never fails to look good.   I promise that this operation is easy and will not disfigure your revolver in the slightest.  Just remember that the chamfering should be just barely visible to the naked eye.

Chamfered cylinder and countersink tool.

     Chamfering the chambers does three things for you.  First: instead of shaving off a lot of lead and ending up with an undersized, and perhaps unsymmetrical ball, the ball is ‘swagged’ into the hole, thus making it possible to have a gas tight seal (assuming no trapped powder grains).  Second:  because you aren't cutting lead,  but are swaging the ball in place (with just a very thin ring of lead shaved off), the rammer force is usually noticeably less.  Third:  because some or all of the balls in your cylinder won't be undersized or unsymmetrical by having been cut, each ball should fit the bore and engage the rifling better.  When a ball fits the bore and engages the rifling properly, you should get a much more precise shot.

     In test after test, I put caps only on every other chamber with the two adjacent chambers loaded, but uncapped.  I then would fire the three rounds.  After firing I'd reload and then put caps on the three chambers unfired from the previous round and then shoot them off.  I did this over and over again on several occasions now and you know what?   It didn't work, I never got a single chain fire no matter how many times I tried it.  I would have all these open nipples and never get a chain fire.  I also tried capping one chamber at a time and I couldn't get it to chain fire that way either.  To me, this is very strong evidence, if not exactly proof positive, that poor fitting caps (or in this case, no caps at all) have nothing to do with chain firing.  

     I think that the idea that loose and missing caps causes chain firing came about because when a chamber would cross-fire, the unexploded cap would be blown off the nipple and this made it appear that you lost the cap first and that's what caused the chain fire.  In logic, blaming something on something else that occurred about the same time is called the "post hoc ergo propter hoc fallacy." Although the evidence looks bad, you shouldn't jump to conclusions, but carefully test to see if they are related. 

     Now, having said all that, this goes against years and years of "common wisdom" that smart people have been claiming regarding poor fitting caps causing chain firing.  You are very right to be skeptical so I sincerely invite you to put your mind at rest regarding this controversy by experimenting for yourself.    If you hold the pistol tightly, having a chain fire is not dangerous or painful, so this should be a pretty safe experiment.  Of course, I don't think you will have a chain fire by doing this, but that is something you will determine for yourself.  I suggest you do this experiment because if you find your pistol is immune from chain firing from this source, it will increase your trust in your pistol.