Flintlock hangfire

[RAEDWALD]

I have just been kindly given a flintlock pistol so that I can keep shooting until the 7" incision in my belly seals up following an operation.

The pistol's origins are uncertain but it appears to me to be an old cheap Spanish percussion one which has had the drum replaced by a screw in touch hole and an after market flintlock. Excellent rifling in the barrel.

I have used flintlock pistols before but this one acts differently.

When fired there is a substantial delay between the pan igniting and the main charge going off. The result is that the target is a neat pattern of holes all around the outside of the black as I loose sight of the bull due to flash and smoke before it fires. I know that there is always some delay but my previous one had only the tiniest of delays. The touch hole is clear and the barrel in excellent condition. The lock works properly. The pan fired with the old crumbly edged piece of flint it came with and a new amber flint.

The only diagnostic item I can give (other than the hangfire) is that the sparks look more towards the orange/yellow than the white/yellow of my old pistol. I can see no reason why the firing pan should take so long to ignite the main charge once it has itself ignited.

Any cunning plans?

 

[tenngun]

You say the touch hole is clear, but how big is it? A 1/16 is pretty much minimal IMHO. 3/32 isn't to bad.
Is the touch hole too high or low? It should be at the 'sunset' position, if not you may have to pull the liner and replace it with another and then redrill the touch hole.
Where ever the hole is priming should never cover the hole.
Between shots swab and listen for air blowing out the touch hole. I blow down the barrel but some folks frown on that practice.

 

[Zonie]

I pretty much agree with tenngun.

The most likely cause of a slow ignition after the pan flashes is the touch hole is too small.

It should be 1.5 to 2 mm in size.

As the gun was converted to a flintlock it might be a good idea to remove the vent liner and check out the area that is under it.

If it goes straight, directly into the bore, no problem.

Some guns were made with a small flame channel hole that connected the percussion nipple with the bore. If that's what is happening with this pistol, do what you can to open up that connecting hole to a larger size (without damaging the vent liner threaded hole).

 

[RAEDWALD]

The touch hole is quite large enough and goes direct to the bore, at the sunset position and I have checked the inside with an endoscope. All seems as it should be. The black powder is the same as with the previous pistol. The priming powder lies the same as with the previous pistol.

I remain puzzled.

 

[Zonie]

Is the length of the vent hole long?

That is, is there quite some distance between the powder charge in the barrel and the exterior face of the vent liner or, is the inside of the vent liner enlarged on the "bore side"?

The closer the main powder charge is to the outer face of the liner, the more likely is is that the powder will ignite rapidly.

This is why vent liners like Chambers, White Lightning liner has a large cavity in it.

The cavity allows the powder in the bore to get to within .7mm of the outer face.

Several other vent liners made by small factories have this internal configuration but many "home made" liners do not.

 

[coloradoclyde]

Dull flint, soft or poor sparking frizzen, poor geometry, or a slow lock......
Have a friend film it...so you can evaluate it..
If the lag time is between the flash in the pan and the gun going off then I would say...Probably touch hole size.....If the delay is from the time the flint strikes the frizzen to pan ignition then you have a flint frizzen problem....

The pan on a really fast gun will ignite before the frizzen is thrown fully open.

 

[RAEDWALD]

The barrel wall is @ 5.2mm thick so, with the countersink on the exterior face of the touchhole liner, the actual hole depth is probably about 4mm. As to whether the liner is coned on the inside I do not know but it looks like a professionally made liner and it is not visible inside to my endoscope.

It made me put the endoscope back down the barrel to see how a wire would come out in the barrel down the touch hole. Came out behind the breech face. However, checking out the breech face with some extra light from an upside down bore light, I can now see that it is indeed a converted percussion pistol. The breech face shows half of the old drum interior drilling is still in the breech face. The wire put down the touch hole reaches into this hole rather than directly into the full bore.

I shall have to try it with the pistol tapped on the side to ensure that this 'half drum' is full of powder up to the new liner. I hypothesise that the powder is not reaching into this space so the burning priming powder has to reach inside until it reaches the main bore. The flat breech face, into which the old drum set, is just in front of the touch hole. Clearly the percussion cap could reach down the drum and be ejected into the rear of the main charge. Now the priming charge has to reach into the space left in the breech face by the removal of the original drum and then ignite the charge. If I can ensure that the main charge fills up the old drum space then the priming charge can reach it just as a flint lock should. I shall trial this at the range on Saturday.

Sometimes you just need to talk to someone else to get your own thinking in order.................

Colorado. The pan ignites quite fast so I doubt if the cause lies in the pan or lock. Pull the trigger and the pan goes 'whoof' straight away. Then the pause before it goes 'thump'. Reminds me of my old Army drill timing; whoof, 2 3, thump 2 3.

 

[coloradoclyde]

The fun and frustration of flintlocks...... :idunno:

 

[Larry Akers]

I was going to suggest you look in the touchhole after loading to see if the charge powder is up to the hole, but it sounds like you already have that covered.

 

[Tom Compton]

I advocate a touch hole be at least 1/16" dia and not over 5/32" on mid bore rifles. Yours sounds as if it could be too large and pressure having to build before high enough to initially move the ball. Similar to a Roman candle building pressure prior to the "whomp".
TC

 

[RAEDWALD]

Just to report that I have cleaned the breech and the residual drum insert hole in it throughly. Took it out again to test. Tapped the powder down but the delay is still there.

The delay is clearly inherent and the pistol is not worth further action though I suppose one could remove the breech plug and cut it back to a flat face.

 

[Don Steele]

That's the best solution I can come up with. Re-breech the barrel and essentially start over. :thumbsup:

 

[Patocazador]

Try once again. Place a wire in the touch hole prior to loading. When loading apply light but ample pressure to get the rod to your witness mark. Remove the wire. Fill the pan with 4F and fire. Also, when swabbing between shots don't enter the chamber with your wet patch.

If this doesn't work, start over.

 

[nhmoose]

To fix this I would use a round nose end mill to open the breech plug up to the liner. It will not weaken it as the threads are already been cut. Only full threads are for strength IMHO

 

[don hepler]

A friend of mine had a similar situation, and a gun smith ran a ball endmill down through the touch hole and cleared it out. It probably could be done with a Dremel tool, as long as the breech plug threads were not compromised.

 

[sixpak1]

make sure you are using black powder and not a black powder substitute like Pyrodex as that will cause a delay for sure

 

[M. De Land]

Try some Null-B or Meal-D powder from Swiss and Goex respectively and bank it away from the flash hole.

 

[Mike M.]

What are you using for a propellant charge? 3F is good...but a lot of the top MLAIC Cominazzo shooters are using 4F. It makes a difference.

 

[M. De Land]

The two I mentioned are faster than 4F which I also have on hand.