View Full Version : So what causes chain fires?

June 19, 2010, 10:04 AM
I always thought chain fires were caused by flame reaching the powder by getting past the ball as suggested by uberti documentation.

But after reading on here, some suggest otherwise? What causes it then?

Will a wad help? Or only help cleanup? So is it a waste to put lard on the ball or bore butter?

June 19, 2010, 10:41 AM
Good luck with this one, bigcountry11, you may get as many different opinions as replies. I've never had a chain fire... before I started using lubed over-powder wads I diligently buttered the balls with various greasy goos. I prefer wads to the over-ball lube method.

June 19, 2010, 11:01 AM
Here's another explanation:

It took me a minute or ten but I finally figured it out: The percussion caps were the wrong size for the nipples on the cylinder. I had run out of #10 caps and simply squeezed a #11 cap to a snug fit in the nipples. This is practice causes no harm when I use it on my side-lock .32 squirrel rifle but it proved to be a dangerous practice for revolvers. The flash and flame that engulfed the cylinder was finding its way into the opening left by my “pinching” of the oversized caps. I proved this by loading one chamber with a charge but just capping the others. I would find one cap burned for every two or three firings. When I switched back to #10 caps on this revolver the problem was cured. Save yourself some grief. Stick to the manufacturer's recommendation for percussion cap size.

4V50 Gary
June 19, 2010, 11:30 AM
Elmer Keith thought it was loose caps.

He's smarter than I.

I agree with the smarter man.

June 19, 2010, 12:24 PM
Then, there's this:
From an old Colt Industries pamphlet:
"Percussion caps are now made in sizes from nine to thirteen. Ten and eleven are the best numbers for the small and medium-sized arms, and twelve for the larger sizes, although, as different-sized nipples are sometimes met in specimens of the same model, no hard and fast rule can be given. It is better to have caps slightly too large than too small, as large caps can be pinched together at the bottom enough so they will stay on the nipples, but small ones must be driven down on the nipple by the blow of the hammer, and this process frequently cushions the blow to the extent of producing a misfire."
I've had two multiple cylinder fires, and each time it was the poorly cast roundballs that were at fault, not the caps.

June 19, 2010, 12:36 PM
The main reason for chainfires is either user error usually from the cap or nipple end. Or an incorrect size ball from the chamber end... Anyone who expiriances chain fires from the ball end regularly most likely has a cylinder with out of round holes, or a varied dimension from the end of the cylinder near to the forcing cone to a greater dimension deeper in the chamber...I have seen and measured these instances on various Revs ... Still one may think it's commin' from the flame & gases at the Ball end, and it ain't.
The most well known cause is a bad fittin' cap, bad nipples, or just a fluke...but from the rear of the cylinder is the most true statement of cause. They don't necessarily have to be missin' caps...an ill fitted cap or a nick in the nipple with all caps on will direct gases or flame to the chainfired chamber from the nipple end.
I too agree with Elmer Keith ... cap end if you have the ball in correctly and measured yur chambers with the proper ball mic or three point inside mic to be sure they are round...most cylinders will vary a few 10 thousands of an inch + or -...

June 19, 2010, 12:38 PM
Thing is, people today don’t read books. They just pass internet rumors to each other.

November 1851 Col Colt gave a scientific paper before the British Institution of Civil Engineers, a large section of which was dedicated to the discussion of chain fires.

Colt describes one modification he made “the Author, after much reflection, to give a slight chamfer, so as to deflect, or thrown off at an outward angle, the fire which expanded laterally across their mouths. The reason for this alteration was, that when the lateral fire met the rectangular edge of the orifice of the chamber, the angle of incidence being equal to the angle of reflection, the fire was conducted downward, or inwards to the charge; but when the flame struck the chamfered edge, it was directed outwards away from the charge. Unimportant as this alteration may appear, it has proved so effectual, that if loose powder is placed over the charge, in the adjoining chambers, it is not now ignited when the pistol is discharged. These and other improvements have brought the fire-arm to it present safe and effective condition, and the Author believes, that no casualty can occur, nor that more than one charge can be fired at one time, if the metal is sound and the arm is properly loaded”

He also mentioned chain fires occurring when he enclosed the rear of the chambers. He called it a “shield” I also think one of the improvements Colt alludes to was the open top of the colt revolvers. A solid frame will direct the path of burning powder right back to the nipples.

Chain fires will start at the front, and at the back.

June 19, 2010, 01:01 PM
Thanks guys. I was looking over my dragoon with caps on. And another theory should be there is not enough room between the cap and the metal frame.

So when one took a shot, the recoil might cause the cylinder to slightly move back and cause a cap to go off?

Maybe its stupid and far fetched, Who knows. I just know I don't want it to happen to me.

So one has to ask, do too many people have chain fires with lard over the ball?

June 19, 2010, 01:11 PM
That would be called a slam fire type chainfire ... happens if the nipples are too long or not enough clearance as you said...I truely would worry much about it on a Dragoon ... one of the safest revs you can shoot w/o worry of a chain fire in my opinion. Mine never has... usually it's an 1860 Colt model replica, or a well used original that go off.
Mine were anyway...

June 19, 2010, 01:31 PM
I say it can happen at either end, depending on the gun and its flaws.
Here's a question - has anyone ever had a chainfire with Pryodex? I kinda doubt it.

June 19, 2010, 02:53 PM
Well, I am working from memory so cut me some lack but as I recall the last time I had this discussion one guy used a propane torch and put powder and wads in all the chambers but no caps on the nipples. A quick wrist flip of the torch over the nipples blew all the chambers but the wads didn't result in any firings. Several things were deduced. First, if the wads saved the day then even if the ball is poorly sized or the chamber is out of round- if the wad is used- that ought to help a lot. Second, if a cap on an abutting chamber is loose or gets knocked off on recoil, hot gases could easily ignite the chamber.
As I recall most of these chain firings were really just one other chamber going off, not all six. Usually the faulty chamber was abutting the one lined up with the barrel.
As far as forcing cones, etc deflecting flames into the chamber ends- that could be but the pepper box pistols were notorious for chain firings and they had no forcing cones, etc.
Probably the biggest surprise was that nearly all chain firings occurred on the first cylinder loading for the day- we couldn't figure that one out but surmised that the only difference would be oil still around the caps- maybe capillary action of some sort caused hot gases to get sucked through the nipples.
In any event we never did come up with one cause- we figured oily nipples, loose fitting caps, poor fitting balls and/or chambers out of round.
P.S. on the loose fitting balls, one guy thought on recoil a loose fitting ball could actually slide forward enough that gases blew the powder charge- may sound funny but in many of these chain firings the damage is surprisingly minimal- which might be the case if the ball is already mostly out of the chamber when the powder blew.

June 19, 2010, 03:16 PM
Well, I am working from memory so cut me some lack but as I recall the last time I had this discussion one guy used a propane torch and put powder and wads in all the chambers but no caps on the nipples. A quick wrist flip of the torch over the nipples blew all the chambers but the wads didn't result in any firings. Several things were deduced.He must have assumed that a chain fire is caused by fire going directly into the nipples. I think the loose caps are ignited by flame from firing, then they pop and that is what sets off the adjacent charge.

Fingers McGee
June 19, 2010, 03:17 PM
There are these tiny little microbes that are the world's worst practical jokers. They think it's just hillarious if more than one chamber goes off at a time on C&B revolvers. They are so small and fast moving that the cannot be seen by the naked human eye; even one outfitted with bi or tri focals. The only known 100% effective preventative measure is the use of not less than 35% by volume of unobtainium in casting projectiles. The unobtanium is like garlic to a vampire and repels the microbes. Unfortunately, these pesky microbes multiply faster than a warren of wandy wabbits and are virtually impossible to erradicate. The best you can hope for is keeping them away from a loaded cylinder. Lacking a sufficient supply of unobtainium for bullet casting, tight fitting balls & caps; while not 100% reliable, will hinder microbe movement and are an effective substitute.

Gator Weiss
June 19, 2010, 04:31 PM
Just a couple of years ago, I saw someone fire a very new looking stainless steel Remington revolver at a very popular public range that I sometimes use. All of his chambers seemed to fire normally. The sound on some of his shots was a little different as if the charges were not uniform. Some were definitely louder. They were his only six shots for the day. A problem developed. He was using a tube of patch grease that was commercially produced for BP shooting and probably purchased at the range. He was using dynamit nobel caps and a new batch of speer soft .454 lead ball ammo. I was not watching particularly closely when he loaded, because I was down the line, and shooting and loading my own BP pieces and cartridge guns.

After he finished shooting, I did see him as he tried to pull the pin and drop out the cylinder. The cylinder would not rotate in a complete circle when he tried it with his hand. That was probably why he wanted to get the pin out. He walked up to the range office where there was a guy doing some smith work. He came back to the range a while later. He said he couldnt fire that particular piece anymore. He had in his hand the cylinder pin, which he said had to be hammered or "drifted" out by the smith, who evidentally told him that it could not be straightened. In looking over the pin, it looked normal until you looked near the end at the "pull" or rather the "T" area, where you could see there was a slight warp. At the spot where the warp began was a line that didnt quite go all the way around the pin, that probably would just line up even with the edge of the center boring in the cylinder where the pin passes through it. The framed appeaed normal as did the barrel. The only disturbance appeared to be to the cylinder pin.

In talking with the young shooter, he said he said he had been pouring powder into the cylinder directly from a FFFG powder can. He had no powder measure with him, and was apparently estimating what he thought he needed to pour into the cylinder. He was of the erroneous opinion that if you overloaded a BP revolver, you would not be able to seat the ball below the surface of the cylinder. My guess is that he probably overloaded the piece. It being stainless, it probably had a somewhat harder cylinder pin. If it had been blue, maybe the pin would have been of softer stock and more disturbed under such pressure.

Anyone had this happen before? What would have happened if it was a Colt style weapon? Did the top strap save the piece from futher destruction?

Doc Hoy
June 19, 2010, 05:31 PM
I have experienced one chain fire and that, I am convinced, was because of a poorly fitting cap. I acknowledge the two other causes, (or three if you believe Fingers:D)

June 19, 2010, 07:28 PM
Gator Weiss - I seriously doubt the damage to the cylinder pin in the case you described was done by overloading the gun. It's much more likely that the pin was not fully installed and thus not properly supported on the back end.

I don't believe it's possible to overload a steel frame percussion revolver. The biggest threat to safety in the scenario you described was loading the gun directly from the powder container. That is a serious safety violation.

June 19, 2010, 09:02 PM
I fired an original Gunnison in 1975 w/no knowledge. It chain fired. Scared me to death. I thought the gun was bad,,but later a hunter friend told me to grease it. I've heard that if the ball seats in chamber w/shaved ring it won't pass fire to the next one. Maybe but I grease every chamber since I don't want to experience a miniture gattlin gun goin off!. Also, if your cap doesn't explode your charge and you try to rotate cylinder and it won't-you are blessed. That ball got lodged in the cone. Sometimes it will get into barrel and then you have a real problem when you fire the next one. If a cap explodes or doesn't--check that chamber safely

June 19, 2010, 09:08 PM
I'd like to hear more about that original Gunnison.

June 20, 2010, 03:43 PM
I wish I still had it. I bought it at a road side gas store/fireworks etc.. store in 74 near Augusta Ga. I got some balls/caps and powder in a colgate tooth paste can to go w/it. I took it down to Georgia Southern in Statesboro,GA and lived next to woods. Anyway, it fired!!!! It had an X on the side of the brass frame and I think Gunnison was barely visible on either the frame or barrel side. Hey that was awhile back! I was told when I bought it that it was made in a factory in Augusta during the war. I do remember C.S.A. was stamped on top of barrel near cone. I sold it in 1975 to an antique gun collector near Statesboro for $100.00 One thing I do remember--- I took it apart and the hammer hand was brass!

June 20, 2010, 04:01 PM
All I know is I have one you can't make chain from the nipple end but you can make it chain from the front.

June 20, 2010, 04:02 PM
Wait--I think the X was on the side of the hammer. CRS:confused: But me and my roomate took it apart because it chain fired and thought it needed some real expert fixin:D If I remember correctly, that same X on the hammer was also stamped on the hammer hand. The gun was solid. After learning to grease the chambers, we shot all the balls, powder and caps (maybe 25 or so) with no problems. It had an extra ordinary hair trigger which I accidently shot a trench across my palm tryin to aim it at a bird. Hell,I was 18 or 19 then. Just as dumb as I am now!!! I though I shot my fingers off. I was lucky. Anyway, after renewing interest in these, I grease each chamber w/ crisco. Watch out for a ball getting seated in your barrel. I've seen 2 this year where folks brought in a banna peal! I have never read or heard of anyone hurting themselves badly by these mistakes--but I'm sure it happens.

June 21, 2010, 10:06 AM
I wish I still had it. I bought it at a road side gas store/fireworks etc.. store in 74 near Augusta Ga.

I sold it in 1975 to an antique gun collector near Statesboro for $100.00

Why don't I ever come across these deals?!

June 21, 2010, 10:21 AM
Hawg I think you know that Rems have to have some or a real bad nipples to cet of a chain fire. And I think we that can all agree chainfire event happen at random or if there is a noticable defect or sumfin very wrong with a revolver. It's like shootin' craps you can win or lose on any roll of the dice.

Mike Irwin
June 21, 2010, 10:42 AM
I was popping caps on an Italian repro .36 Navy some years ago to clear the nipples of any oil before I started shooting.

I popped three, and on the third both the third AND the fourth cap popped in rapid but distinct succession, so it appears that caps can be a cause.

June 21, 2010, 11:23 AM
I had 4 chain fires.(probably a better term would be multiple discharges as only the intend chamber and the next chamber in order fired).
All of these occurrances were early in my cap & ball career and all occurred with less than perfect balls cast out of a poor(too hard) alloy.
Since, I have used only dead soft alloy and throw out the less than perfect balls.
In each case the second chamber to fire had an unfired cap securely on the nipple.

June 21, 2010, 11:56 AM
I hate the ask the dumb question.

But happens to shooting hand when these chain fires happen? And what happens the said pistolly.

June 21, 2010, 12:19 PM
I've had two double-fires. Each time, the second ball exited from the left side of the gun at a 45 degree angle to the ground. I wasn't even sure what had happened - just a little extra boom (.36 caliber).

June 21, 2010, 12:42 PM
Nothin' happened to my hand any of the 4 times I had a chainfire. The velosity directly out of the camber the ball only travels about 200fps way less than a paintball gun ball. The barrel length and twist multiplies the ball's velosity. Jus' leaves a lead mark on the frame that wipes off.

June 21, 2010, 01:14 PM
Nothing. Aware something had happened but did not know what until inspection.

Fingers McGee
June 21, 2010, 06:53 PM
Nothing. Found a lead smudge on the wedge that wiped off.


Doc Hoy
June 21, 2010, 07:16 PM
The only experience I had involved that Sheriffs Model as I said.

Brass frame...

It loosened the arbor.

That was a sweet shooting pistol too. Now it is a sweet looking wall hanger.

Such is life.

June 21, 2010, 07:34 PM
Ive only had one chain fire and it caused the chamber to the left of the one being fired to go off.It shot off into the woods at a 45 degree angle and left a little bit of lead on the end of the barrel pin of my 1858 Remmy but it cleaned up easily and left no permanent damage.