A little rant about those dreaded chain fire events

[Mizar]

A disclaimer first - I don't intent to bash on other people, fellow members and etc. but just to offer some thoughts on the subject.

I just read a recent thread in another gun forum in which the OP was discussing his chain fire experience. Nothing out of the ordinary - both the shooter and the gun are fine. It was a .36 cal 1858 revolver. So, the OP mentioned some (for me at least) crucial information - he was using pinched Remington #10 caps. Apparently the nipples are undersized and he had to squeeze those caps a little bit so they can fit without falling off. The problem with this is that you will always get a portion of the cap's skirt not in contact with the nipple - i.e. not a real tight fit, an empty space between the cap and the nipple.

Now, here comes the fun part - for two pages everyone is ignoring that fact and the talk is only about ill fitting balls, crooked chambers, powder particles embedded in the lead projectile and etc. If you refer to the pic bellow, one instantly sees the amount of flash and hot gasses at the rear of the cylinder, not only at the front, as the revolver fires. Isn't it logical to assume that the ill fitting caps were the actual culprit that led to that unfortunate event? I mean, how hard it is for those hot gasses to "sneak in" into that little space left and ignite the next cap? And no, chain fire is very less likely to happen with unprimed nipples just because of the simple fact that the powder charge is about .4 inches away and the hot gas must travel straight down to a very narrow tunnel. Now, compare that to a literally exposed priming compound sitting right next to a hot explosion. I believe that the second is much more likely to cause a chain fire. And also I believe that the vast majority of chain firing events are happening because of ill fitting caps. Not all, but most of them. No matter what the owner said, if those caps can be shaken off the nipples, or they require pinching, they are of no good fit. So, what say you?

Picture shamelessly stolen from "Cap & Ball Revolvers, Pistols and Rifles" Facebook group:

 

[WestKentucky]

One thing very often overlooked is that nipples are tapered. They actually taper fairly quickly. A quick adjustment with a file will shorten a nipple enough to make for a good fit. I have done this many times with percussion rifles and the process would be the same for revolvers. The hammer certainly will still travel far enough to strike the cap. BUT, as a cap ignites it often ruptured and still throws sparks.

 

[ClemBert]

And also I believe that the vast majority of chain firing events are happening because of ill fitting caps. Not all, but most of them. No matter what the owner said, if those caps can be shaken off the nipples, or they require pinching, they are of no good fit. So, what say you?

Yup, too much attention is often given to sealing the chambers and not enough on sealing the nipples. By far, you are not alone in the camp that believes most chain fires start from the nipples not the mouths of chambers. I've seen very credible evidence in the past that suggest you are right on target (pun intended) and most come from poorly sealed nipples.

p.s. Anyone want to experiment and leave the caps off the two nipples directly adjacent to the cylinder locked in breach?

 

[drobs]

I've never had a chain fire.
Before I had the correct sized caps (Remington #10) for my Pietta NMA I was using CCI #11 caps. The CCI #11's needed to be squeezed to fit properly.
I had caps fall off while firing the gun w/ no chain fire.

A test might be to load 6 chambers with powder and wad and alternately cap 3 of 6 nipples. Do the uncapped nipples fire?
Another test would be to load 6 chambers with powder / wad but only cap 1 nipple.

I've played with just shooting powder and wads. No chain fires from the front.

The other variable could be loose nipples with caps firing from impacting the recoil shield. I think we could test that too.

An out of round chamber or chamber with lots of tool chatter could be the source. Anyone want ding up a spare cylinder?



Question is how can we get a gun that we know doesn't chain fire to chain fire?

How about greasy chambers and greasy wads that have been dipped in black powder using the same all chambers loaded (powder and wad) and 1 chamber capped.

 

[Mizar]

I don't doubt that chain fires can start at the front of the cylinder, not at all. Just that it's more likely for them to start at the back, from ill fitting caps. And by ill fitting I mean either pinched to stay in place, or ones with ripped open skirts because they are too small for the nipple and have to be seated with a wooden dowel. Because with those conditions we have the priming compound of the caps sitting unprotected right next to the hot gasses blown from the ignition. And as one can see from the pictures the flames that emerge from there are big enough to not be ignored. Just because it did not happen to some of us does not prove anything.

Those kinds of tests, where a revolver is fired with loaded chambers, but without caps have been done numerous times - the guns would not chain fire. It's just quite hard for the hot gasses to reach thru the small tunnel in the nipple, travel about half an inch distance and ignite the powder charge.

About the out of round chambers - if the deviation in diameter is small, there would be no problems if the balls are oversized to begin with because they will just obturate that hole. If those chambers are so elongated, that the ball would not have enough "meat" to fill the gap then I believe that this condition can be seen with a naked eye. Same with the chatter marks - if they are deep enough to be of concern they can be seen without a problem. All in all, those are easy to spot problems and almost as easily corrected. It's up to the shooter to use his head not only for wearing hats on it... Not to mention, that in today's replicas such problems are very seldom found - as Jim (expat_alaska) has pointed out numerous times, the CNC machining really pays off in the quality department. So this conditions are more like a thing of the past, not something that we will encounter on new revolvers.

I also doubt that greasy, filthy chambers with 10 grains of black powder sticking on top of them to be the culprit, as the ball (or the conical bullet) will scrape that off when it's rammed into the chamber. To embed a speck or two of black powder into the lead ball (bullet) when rammed home - sure, it can happen. But to embed a whole trail of black powder, capable of carrying flame into the chambers? I highly doubt that.

P.S. I started this thread more like to share my amusement that some people would ignore a simple and obvious fact and jump to any sorts of bizarre conclusions, while the most logical explanation is right in front of their eyes.

 

[drobs]

It seems to me if damaged, cut, or out of round caps are the cause, we should be able to replicate a chain fire.

 

[paul harm]

All the years I shot pistol at Friendship it was always thought it was caused from the nipple end of the cylinder. This was from people who shot for years and years. Right or wrong, I don't know. To me, it seems real hard to do it from the bullet end. If you're shaving off a ring of lead that means the RB is rubbing all the way around. There is no gap. It's sealed. And with a pill or cookie under it, or grease over it, how does the flame travel around it to reach the powder ? In the back I have trouble believing the flame travels to the next nipple [ without a cap ] and makes a 90 degree turn into the nipple and travels down it to ignite the powder. There would have to be a ill fitting cap with a gap on the side and top to redirect the flame. I don't know which way it is. I guess it's just a natural unexplainable phenomena.

 

[Choctaw]

I've never experienced a chain fire either but it has been my understanding the majority initiate from the nipple side of the cylinder. I haven't greased a chamber in years.

 

[J-Bar]

I use home cast balls which have a flat spot where the sprue is cut. I put the flat sprue scar next to the powder when loading to avoid a gap between the ball and cylinder wall. I do not use a wad between powder and ball, and only a scant amount of lube over the ball (not nearly enough to seal the chamber.). Shaving a lead ring has always been adequate prevention for my guns. My few chain fires have occurred with ill fitting caps being burned for practice, not with caps that fit nipples well.

 

[daboyleroy]

WOW !!!.
First picture 2nd row!!!

 

[midland man]

lol this thread is funny to follow well so I have been shooting my 1851 navy and my caps don't fit perfectly but I yet to experience a chain fire! so makes me wonder if theres a tiny rust hole or holes in the chambers that could be firing off other cylinders??

 

[Ephraim Kibbey]

From a package of Remington #11 caps: "CAUTION: May explode if subjected to percussion, sparks, flame or intense heat."
From a package of CCI Musket caps: "WARNING: Primers may explode if subjected to impact, electric shock or intense heat."

I would think a discharging black powder revolver chamber would provide sparks, flame and intense heat!!!
I guess that it is a testament to how well most caps can fit on the correct nipples that this doesn't happen more often.

I would think a more exacting (not to mention safer) test would be to load only one chamber taking your normal chamber mouth precautions and then cap all of the nipples (including those over the empty chambers) with your pinched or ill fitting caps.
When you fire the loaded chamber, if other caps are ignited by that blast you have safely proved this theory with your combination of components!!!
And you need to buy either different caps or different nipples.

 

[whughett]

View attachment 792867
WOW !!!.
First picture 2nd row!!!

Explains why the cylinder is so sooted up as well as the hands. I shoot under a covered firing line, on certain overcast days the fire works can be spectacular, even to the wad trailing a sparky tail downrange.

 

[paul harm]

J Bar - most the guys I know load the flat up, facing the muzzle. The air traveling around the back of a projectile will effect accuracy more than the front of the projectile. Another way of saying it is the front can be marked, or deformed, and it won't make a difference. Now deform one side of the back and accuracy is going to be poor. If that flat is off to one side it isn't gonna group as good as it could have. Just a thought.

 

[rodwha]

J Bar - most the guys I know load the flat up, facing the muzzle. The air traveling around the back of a projectile will effect accuracy more than the front of the projectile. Another way of saying it is the front can be marked, or deformed, and it won't make a difference. Now deform one side of the back and accuracy is going to be poor. If that flat is off to one side it isn't gonna group as good as it could have. Just a thought.

This is one reason I prefer the Lee molds for a ball. But I still liked to place this tiny sprue at 90* so that it is among the edge that gets shaved off.

 

[tpelle]

I'm glad to see this topic come up, and I believe that Mizar is 100% correct - most chain fires come from ill-fitting and pinched caps.

When I first started fooling around with percussion revolvers I believed what I read on the Internet - that chain fires were caused by the flash from the barrel/cylinder gap spreading to adjacent chambers and either igniting spilled powder or unburned powder from previous shots leading the flame somehow down through the over-ball grease, past the ball, and past the under-ball wad. But this surely did mean that a lot of things had to go wrong at the same time.......so I was a little suspicious.

Then I read THIS article, where this guy in Norway actually did his best to TRY to cause a chain fire from the front. He even went to the extreme of actually pouring fresh powder all over the front of a loaded cylinder, but was still unable to make a chain fire happen. Here's the article (I'm surprised it was still out there!):

https://svartkrutt.net/articles/vis.php?id=13

So stopped with the under-ball wads, and smearing Crisco all over the front of the cylinder. I load powder, press in the ball, then cap and shoot.

But I run Treso Nipples on my 1860s, and use nothing but Remington #10 caps.

Never had a chain-fire.

 

[midland man]

the only reason I use a lubed wad I make is to keep the bore lubed and the cylinder pin from freezing up so fast as I used to use only powder and ball and the cylinder would seize up much sooner, so once I started using my homemade lubed wads I was able to shoot much longer without the cylinder freezing up on the cylinder pin! so tpelle how do you keep your cylinder spinning for extended shoots!

 

[Tommygunn]

A historical note, if you will;

It's my understanding that the reason most (but not all) cap 'n' ball revolvers have their nipples recessed into sockets, as on Colt's and Remmies, is that early manufacturers thought it helped guard against these chain fires by having that inter-chamber "wall" between the nipples.
Now, as many will observe, this feature certainly does not work in a fool-proof way, as improper fitting caps may still allow it.
But those sockets cost $ and time to mill, so even Samuel Colt and Eliphat Remington, and others (probably not Mr.Starr) seemed to consider the sockets to have a worthwhile purpose.
Could they have believed what many here do ---- that chain fires came from that end of the cylinder?
Just sayin' .

 

[drobs]

I'm glad to see this topic come up, and I believe that Mizar is 100% correct - most chain fires come from ill-fitting and pinched caps.

When I first started fooling around with percussion revolvers I believed what I read on the Internet - that chain fires were caused by the flash from the barrel/cylinder gap spreading to adjacent chambers and either igniting spilled powder or unburned powder from previous shots leading the flame somehow down through the over-ball grease, past the ball, and past the under-ball wad. But this surely did mean that a lot of things had to go wrong at the same time.......so I was a little suspicious.

Then I read THIS article, where this guy in Norway actually did his best to TRY to cause a chain fire from the front. He even went to the extreme of actually pouring fresh powder all over the front of a loaded cylinder, but was still unable to make a chain fire happen. Here's the article (I'm surprised it was still out there!):

https://svartkrutt.net/articles/vis.php?id=13

So stopped with the under-ball wads, and smearing Crisco all over the front of the cylinder. I load powder, press in the ball, then cap and shoot.

But I run Treso Nipples on my 1860s, and use nothing but Remington #10 caps.

Never had a chain-fire.

I don't think the author of that article proved much of anything. He was able to get a chain fires in both the front and the back of the cylinder but neither of his chain fires proves his point one way or the other.

In order to get a chain fire from an adjacent nipple he had to fill that adjacent nipple with black powder. While I have heard of BP shooters priming nipples, it doesn't prove his theory. Mizzar's theory of the priming powder being ignited in a poor fitting cap on an adjacent chamber makes more sense to me.

Chain fire 1 (back of cylinder).
"Then it was time to try to ignite the round from the opposite side of the cylinder: I loaded a .451" ball with no filler, wad or grease and put a small amount of 3F black powder on the neighbour chambers nipple area and lit the fuse. I did not put a cap on the nipples. Nothing happened, until I lit the fuse the 9th time. The loaded chamber went off with a bang."

Chain fire 2 (front of cylinder)
"Just to try to get a multiple discharge I loaded all six chambers with 30 grains of FFFg Wano and put a wad lightly greased with Bore Butter on top. Then I capped the revolver and the blanks without getting any frontal ignition when I shot them. I proceeded with the same load, but this time I put a ball in every second chamber. I capped all six chambers and fired the balls only. The chambers only protected by a felt wad did not go off. I then loaded the cylinder ditto, except this time I loaded the chambers without balls to the brim with powder before I put a felt wad over. The wad was in other words flush with the chamber mouth. This time I finally got to experience a frontal ignition. It happened as I fired the second ball. After I had fired all of the three chambers loaded with ball two of the felt loaded chambers were still in place."

 

[J-Bar]

J Bar - most the guys I know load the flat up, facing the muzzle. The air traveling around the back of a projectile will effect accuracy more than the front of the projectile. Another way of saying it is the front can be marked, or deformed, and it won't make a difference. Now deform one side of the back and accuracy is going to be poor. If that flat is off to one side it isn't gonna group as good as it could have. Just a thought.

Arthritic fingers! When I try to put the sprue scar up it always tips to the side. I put the flat spot on the face of the cylinder and then slide the ball into the chamber mouth; perfect. Accuracy is adequate on steel plates at 8 yards.

 

[Mizar]

Actually the theory is not mine, but it's a view shared by lots of (way more than me) knowledgeable shooters. It's just a reminder, that while we make damn sure that the cylinder is sealed well at the front, we should not forget to seal the back also. And I want to make it clear - this is not "only the caps matter, because only they cause chain fires" kind of view. Not at all. There is plenty of evidence that ill fitting projectiles, or bad chambers can and will cause chain fires.

 

[Roger Laird]

Only have had one chain fire in 15 years shooting cap and ball revolvers.I was using conical bullets.I have never used them since.

 

[Steel Hayes]

It was a .36 cal 1858 revolver. So, the OP mentioned some (for me at least) crucial information - he was using pinched Remington #10 caps.

Going back to Mizar’s OP, I’d like to know what kind of nipple the guy was using that you would have to squeeze a #10 cap?
I don’t think I’ve ever seen one that small(unless it was customized) made for a percussion revolver.

 

[drobs]

Actually the theory is not mine, but it's a view shared by lots of (way more than me) knowledgeable shooters. It's just a reminder, that while we make damn sure that the cylinder is sealed well at the front, we should not forget to seal the back also. And I want to make it clear - this is not "only the caps matter, because only they cause chain fires" kind of view. Not at all. There is plenty of evidence that ill fitting projectiles, or bad chambers can and will cause chain fires.

Yeah there's a ton of variables.

 

[Mizar]

Steel Hayes, stock Pietta nipples I suppose - they are known for inconsistent dimensions between batches. Let me give you an example - three .44 Piettas, produced in 2017 and ordered within two months from the same vendor. Two 8" NMA's (belonging to some friends of mine) and a 1860 (mine). Caps tested were Dinamit Nobel RWS 1075, all from the same 2500 pcs. sales package (confirmed). They are the same fit as Remington #10 by the way.
First NMA - caps fit OK. Not perfect, but OK - no gaps, they do not fall from recoil, takes some force to remove them when seated.
Second NMA - nipples shortened to .01" and caps still fit loose.
1860 - nipples shortened (and chamfered) to .008". Caps fit perfect - takes some force to seat them, but finger pressure is enough to seat them fully.

I did change them with Tresos shortly after, that was my original intention, but I wanted to have a spare set of properly fitted nipples just in case.