That was a good article to read. Thanks for posting it. However, the article did nothing to address the OP's question regarding chain fire which he refers to as "multiple flash overs". The article concerns the safe capping of percussion revolvers.
To the OP the prevention of chain fires is two fold. Sealing the muzzle of the chambers properly and sealing the nipples properly.
Sealing the chambers requires that the chambers be uniform in their "roundness" and the use of a soft lead projectiles, also uniform and without defects, that are larger than the chamber diameters. Some folks will use lubricated wads, fillers, and/or "grease" sealants as an added preventative measure. The selection and use of such materials is a long debated topic on this forum and others.
If you take the steps, as highlighted above in blue, you will not get a chain fire initiated from the chamber muzzles. About right now there are a few red faced members
who are going to want to debate me on that note.
With regard to chain fires initiated from the rear of the chambers AKA the nipples...again, this will require nipples uniform in their roundness without defects. Reasonably tight fitting caps that do get jarred loose when firing will be a key feature in preventing chain fires initiated from the nipple area.
Now that I've had my say....let the religious debate begin!
p.s. I just noticed that this post is post #666 for me. Excuse me while I go drink some holy water...or beer...
Clembert,
I'll say it again:
It is one of many tests that have been conducted trying to determine how chainfires occur and how much of a danger do they pose.
Maybe I should have said it is one of a series instead of one of many. It is the only one that looked at the danger from the projectiles that has been properly documented that I know of. There had been a bunch of conjecture, rumors, stories suppositions, opinions and even anecdotal "evidence" from shooters saying that multiple balls went out and hit the target or backstop.
Rowdy was adamant that it wouldn't be dangerous (and he should know), Scout decided to put an end to it by conducting a well documented test. That is what my post was specifically about. It's not about after the fact accounts, eyewitness or not; because we have learned how unreliable they can be even if the witness testifies to the best of their ability.
I am out of town right now so I don't have access to my files. There have been other tests where they set off as many as 5 chambers at once. The one test shot at carboard as well and advised that you would have 5 deadly projectiles. Scout machined the cylinder ring and recorded the first chronographed velocities from a cylinder alone that I am aware of.
Even in the situation above you have to be careful about what you report, you can only make claims that are supportable. The test that showed the 5 holes on the target "looked" VERY bad. But they really had no idea how powerful the hits were. Some of us were suspicious because the holes looked torn instead of the round grey/black tinged holes you normally see from a ball penetrating the cardboard at normal velocities.
The 5 shot test used model rocket motor igniters on all five chambers. They left the 6th at the rammer out fearing they would destroy the pistol. That was a projectile test. Then there have been actual chainfire tests. The simplest have been on machine rests or anchored with the chamber under the hammer capped and the others uncapped. It is frightening how often they will go off in that configuration.
We chose to test front chainfires and did two types of tests. One with the cylinder on the pistol and one with the cylinder dismounted. We could not get a chain fire at all on the pistol. We tried everything from the infamous casting wrinkle to literally cutting grooves on the sides of balls allowing a path. No lube, just intentionally loose fitting balls and openings cut into them. We even dribbled powder all over the fronts of the chambers to simulate bad loading hygiene.
We got tired of loading on the Ransom Rest and decided to just try to set multiple chambers off with the cylinder off and pointing up at an angle to allow a lot of powder on the chamber fronts ( mean a LOT). We used both nichrome igniters and cannon fuse. The cannon fuse was bad about setting off any loose powder and the front even flash off once before the one chamber it was supposed to ignite from the rear. We then switch to nichrome motor igniters until we ran out.
We were finally able to get flash overs, but only after carving deep grooves and in one case a drilled hole. Then we added 4F flintlock priming powder down the holes.
The problem with this account I am giving is that I am all over the page trying to recount 3 different tests. Two weren't ours, and ours had a matrix of different conditions I am not doing justice to in this post.
Can you get flash overs from the front? Yep, but be prepared to do things no self respecting cap gun shooter would ever do.
If you get bored before I have a chance to dig the info up, try it yourself. See if you can get one to go off from the front. Oh, I almost forgot to mention that we put 12-28 set screws in five of the cone holes to assure there was no chance of igniting from the rear. They aren't easy to buy so we took some 1/4-28 allthread stock and turned the O.D. down to Ø.215 then threaded it with a die I keep to freshen cone threads ( have taps as well) then cut them to set screw length and slotted them. Or you can do what another experimenter did and filled some old cones with JB Weld (DOOOOOHHHHHH!!!! I hate it when I miss the obvious)
~Mako
