Whooosh!

[Natureboy]

   Yesterday I had a strange experience.  My black powder club had our monthly meeting on an unusual rainy day in Oregon.  On about my fifth shot, the pan flashed but the load discharged through the vent, with the title sound.  I pulled the ball, and the patch was disgusting.  My supposition is that because we don't level and prime our guns until we're at the firing line, the 25-foot walk to the line allowed some rain down the barrel, wetting the forward part of the
charge so the rest found its way out through the vent.  From now on, when it rains, I'll either carry the gun low with my finger over the muzzle, get a tompion or even just a cork to keep the rain out of the barrel.  I'll try to remember to pull out the cork before shooting.  This never happened when I was in the Army, and I seem to remember lots of monsoon rain in those days.
   Does anyone agree with my conclusion?

[smokinbuck]

No, if your ball and patch were tight they should have kept the powder charge dry. I would definitly NOT use a cork or put my thumb over the muzzle. If you want to cover the muzzle use a penny balloon over the muzzle, never in the barrel.
Mark

[Kermit]

...the load discharged through the vent, with the title sound.
...the patch was disgusting.

I'm not sure I know what you mean by these. And surely the entire main charge didn't escape through the vent!

I lived/worked/hunted on the wet side of the Olympic Penninsula for five years. I joked that we had to learn to shoot flintlocks under water. We got up to 200 inches of rain a year, with about half Oct-Nov-Dec, right in hunting season. I used Mark's balloon trick on the muzzle (shoot right through it) and sealed the pan with goops from Vaseline to Crisco. I tried to keep the lock out of the weather. I had one hunting misfire in 5 seasons, and the prime didn't light. When the pan would go, so did the main charge.

I can't see walking 25 feet causing the problem. I think Mark's right that you need to consider a tighter ball/patch. And if they'll let you, walk to the line muzzle down when it rains, plug the vent with a feather that you pull after priming and just before closing the pan.

[longcruise]

If your entire powder charge ignited an discharged through the vent, then I think you somehow short charged while loading.  Unless pulling the ball showed a large amount of wet powder in the barrel, then it would not seem to be rain infiltration.

[Natureboy]

  I'm pretty sure I didn't short-charge the load.  I have 1/16" brass wire gizmo that I put into the vent when loading to prevent the 2FG power from infiltrating the vent, and I pull it out just before priming the pan.  I tried to make sure my wide-brimmed hat covered the pan when priming.  I've had a lot of trouble with FITP with this gun, and I'm considering having the vent drilled and a vent liner installed, centered over the pan instead of where it is now, slightly back of center.  The ball and patch combination I use, pre-lubed linen with a .530 ball, is tight enough to require hard pushing to seat the load, but not so tight that I have to hammer on it.  I don't want to flat-spot the ball when ramming.  I'm going to experiment with different patch material when I get my shipment of Mr. Flintlock lube, which most folks on this forum praise.  This is the first time in about 150 shots that the load has blown out through the vent.  I provided some comic relief for the other club members, who were also dealing with the rain.

[hammer]

Perplexed.  You seem to suggest the powder burned like a firework rocket rather than a single explosion.  That would certainly account for the horrible fouling.   So why would the powder fizz rather than bang?
Damp powder seems to me the most likely cause.  Especially as it was raining at the time. 
A few raindrops wouldn't get past a patched ball.
Reminds me of the old phrase 'keep your powder dry'.

Peter.

[ken]

I would guess that you got the powder wet or damp before you put it down the barrel. It does not take a lot , a drop from your hat  or just from the rain itself. Happens when we get to talking and distracted. make shore that your vent has not gotten to large  or been shot out .     ken

[Candle Snuffer]

I too am thinking the powder charge may have gotten a rain drop or two combined with the dampness of the previous powder charges drawing moister after the shots taken making the load foul enough to cause this. Really don't know what else it could be? It does surprise me that the patched ball was not at least pushed forward in the bore, or was it?

[Standing Bear]

Sounds like a light charge that didn't build enough pressure to push the ball out. I've never seen a damp charge do this heck never had a damp charge.

If powder clumped in the measure and only a little got down the barrel it could act like this.

Jus thinkin

[bob in the woods]

Damp powder can burn slowly, more like a fuse. I've seen it before. Not enough pressure builds to expel the ball, but it probably did move forward a bit. We have had scheduled matches that were held rain or shine, and sometimes it has just poured !    I've successfully used my flintlock in these, when a lot of the percussion shooters had trouble. One really big help was to pre measure my charges. I have a bunch of 35MM film cases that I use to hold the individual charges for my long range bullet rifle.  [  For long range use, 800-1000 yards , I weigh each charge on my electronic scale…need to to be competitive ]

[Natureboy]

  I've been thinking about the damp powder issue too.  I store my cans and horn in an unheated room which doubles as my photo studio, and I'm wondering if I should hang the horn in our front room, which has a wood stove.  20 feet or so away from the stove would keep it in a dry environment without the danger of combustion.  Our loading benches are
covered, but the range is down in a steep valley where the air is pretty humid when it rains.  Black powder will absorb
moisture from the ambient atmosphere.  Since I don't hunt and only shoot targets, maybe I just won't try shooting when it rains anymore.  In Oregon, we have two seasons--wet and August.
   I make sure to plug the horn as soon as I've measured the charge, and I don't think any drops of rain hit either the horn or the measure, but you never know for sure.  I'm wondering if the powder, which is hydroscopic, just got a little damp because of the environment.  The guys shooting cappers had a lot of misfires, too.
   To all you fellow veterans out there:  WELCOME HOME!

[D. Taylor Sapergia]

Your problem almost certainly was from the priming powder, and possibly the main charge being dampened.  It has happened to me in a driving rain while hunting.  I was hunting grouse along a bush line with my Brown Bess (10 gauge) loaded with black powder and shot.  During the course of my trek my priming powder became spoiled, and when a bird rose, I swung, pulled the trigger, and continued to follow through the entire several-second discharge of the entire load of powder through the vent.  There was a lot of fizzling and popping, but the main charge did not go off properly.  I ended up watching the bird cross the meadow and land in the brush some distance away.  I had to pull (draw) the wads and shot, dry the pan as best I could, and start again..  Such is the nature of hunting in the rain with a flinter.

[Natureboy]

I use 4FG priming powder, and I've read here and elsewhere that it is the worst for moisture absorbency, so that makes sense, too.  The main charge did sound like a bottle rocket, so maybe, as you say, both powders got wet somehow.  And this wasn't hunting out in the rain, but loading under an open roof, the only exposure of powder occurred when I primed the pan at the firing line.  I tried to have the brim of my hat over the pan, but I'm a bit leery of having any body parts over either the pan or the muzzle.  Should I store my powder in a warmer, drier room?

[smallpatch]

I had the same thing happen at our last club shoot.

Totally DRY day, but a shot with a 15g limit for the main charge. Fire shot out the touch hole like a Roman candle, and the ball moved about a foot in the barrel. Co2 charger to get it out.
Obviously I missed!
Not enough umph to move the ball?

[little joe]

A couple of times in the last 40 yrs of shooting flintlocks I have short started a ball and did not shove it down. At the line to prime, the muzzle , quite often is angled down. When you shoot the powder burns as a powder train and most of the charge, or all escapes through the vent. More human error.

[Natureboy]

  My ramrod is marked with a sharpie to show when it's empty or properly rammed.  I always check that mark when
loading the main charge.  The Thomson Center folks sacrificed a few of their guns to show what happens when you fire with the ball not seated fully, or there is a blockage, like mud, in the barrel.  Those barrels peeled like bananas.  When I pulled the ball, the patch surrounding it looked like it was burned, so I think the "roman candle" scenario fits.  The question I still have is whether or not I should store my powder in the front room, a comfortable distance from the wood stove, so it stays dry and doesn't absorb moisture from the ambient, humid atmosphere of rainy Oregon.  That ball puller was a very good investment.

[omark]

Yes, storing your horn in the front room would be a good idea. Mark

[Pete G.]

I had the same thing happen at our last club shoot.

Totally DRY day, but a shot with a 15g limit for the main charge. Fire shot out the touch hole like a Roman candle, and the ball moved about a foot in the barrel. Co2 charger to get it out.
Obviously I missed!
Not enough umph to move the ball?

Sort of like that tree in the forest thing....
If the ball does not leave the barrel is it really a miss?

[Vomitus]

   ...or, you had water in the breech before you reloaded?