Firing a flintlock pistol with damp powder

JayD · Jun 23, 2010

All right, I think I've got a pretty good grip on what would happen if you were to fire a late 18th century flintlock using slightly damp powder, but I figured I'd better run it by the experts. After all, it's pretty important part of my plot.

So, we have a flintlock pistol cocked, loaded with mildly damp powder, and primed with the same powder. When fired, there's a very good chance it will:

-Make a lot more smoke than usual

-Fire the bullet at a lower velocity

-Take a moment or two longer than usual for the main charge to ignite

-Or not go off at all, like a "flash in the pan" situation. In which case the shooter might try re-priming and re-firing the pistol before discarding it, as worming out a round would be a lengthy task.

Please let me know if I'm wrong on any point or forgetting anything, and thanks in advance for the help

johnnysannie · Jun 23, 2010

I've shot black powder rifles, similar but not the same, but in my humble estimation, damp power would cause a misfire - the flintlock wouldn't fire. "Keep your powder dry" was a big thing back in the flintlock day.

Stanmiller · Jun 24, 2010

Not only that but a flintlock requires the flint to create a hot enough spark to ignite the powder in the flash pan. If the flint is wet, you may get a weak spark or no spark at all.

So keeping the lockwork covered is another important element of shooting flintlocks. Percussion caps all but eliminated that problem, and would even fire damp powder as they produce an actual flame rather than just a spark.

--Stan

Saskatoonistan · Jun 24, 2010

Putting on my former ammunition tech hat on for a second ...

Black powder is extremely hygroscopic (it's a word, serious!) which means that it will actually draw moisture from the air so it absolutely must be stored in very dry conditions. Based on all my experience using black powder, even when it's slightly moist, you're probably going to get a misfire or it will dramatically affect its burn rate and therefore, the muzzle velocity of the projectile. Will you get more smoke than normal - no - but bear in mind black powder produces HUGE amounts of smoke and propellant gases when it's bone dry. Hope that helps.

WriteKnight · Jun 24, 2010

Most likely scenario... no ignition. Misfire. The chance of a 'slow fire' is probably less than thirty percent. But you're in a fictional situation... you get to decide what 'slightly damp' means.

Chase · Jun 24, 2010

JayD, all the comments above are gold. Here are a few "finer" details:

I just returned from a rendezvous at Yamhill, Oregon, where the gentle rain provoked not-so gentle oaths at many damned damp powder misfires. Yep, "keep your powder dry" is a must!

Even more so for flintlocks. As said, your flint, your frizzen, and your pan must be bone dry.

Most flintlockers use FFg (coarse granuals) black powder behind rifle and pistol ball; however, in the pan of serious shooters, only FFFFg, (fine granuals) are sprinkled--the best pan powder we can find these days (5Fg is now rare).

This priming powder is even more susceptible to moisture, and most flintlockers keep it in a special horn undercover. While hangfires (slow ignitions) and squibs (weak shots) are certainly possible from slightly damp powder, the only result I’ve ever witnessed from moisture is no ignition whatsoever.

Another term: "Flash in the pan" is an analogy for someone showy but ineffectual. The real thing is damp FFg in the pipe failing to ignite from dry FFFFg in the pan.

I hope you can use some of this in your story.

Stanmiller · Jun 24, 2010

Chase said:
JayD, all the comments above are gold. Here are a few "finer" details:

I just returned from a rendezvous at Yamhill, Oregon, where the gentle rain provoked not-so gentle oaths at many damned damp powder misfires. Yep, "keep your powder dry" is a must!

Even more so for flintlocks. As said, your flint, your frizzen, and your pan must be bone dry.

Most flintlockers use FFg (coarse granuals) black powder behind rifle and pistol ball; however, in the pan of serious shooters, only FFFFg, (fine granuals) are sprinkled--the best pan powder we can find these days (5Fg is now rare).

This priming powder is even more susceptible to moisture, and most flintlockers keep it in a special horn undercover. While hangfires (slow ignitions) and squibs (weak shots) are certainly possible from slightly damp powder, the only result I’ve ever witnessed from moisture is no ignition whatsoever.

Another term: "Flash in the pan" is an analogy for someone showy but ineffectual. The real thing is damp FFg in the pipe failing to ignite from dry FFFFg in the pan.

I hope you can use some of this in your story.

Good info, Chase. I was hoping you'd chime in with actual experience here. In my state we can't buy black powder without an FFL so have to use Pyrodex or other modern black powder equivalent, which isn't as susceptible to moisture as true black powder. But it doesn't make as much smoke either, which is part of the fun of BP shooting.

Tsu Dho Nimh · Jun 24, 2010

JayD said:
So, we have a flintlock pistol cocked, loaded with mildly damp powder, and primed with the same powder. When fired, there's a very good chance it will:

-Or not go off at all, like a "flash in the pan" situation. In which case the shooter might try re-priming and re-firing the pistol before discarding it, as worming out a round would be a lengthy task.

None of the above:

If you re-prime on top of damp powder you still have damp powder!

My "Black Powder Bible" says you have to remove the ball, remove the wadding, dig out the main charge (which will have packed down real good because of the dampness), clean the firing mechanism and barrel, reload gun properly with dry powder and primer.

Or grab the gun by the barrel and start bashing!

JayD · Jun 24, 2010

Chase said:
JayD, all the comments above are gold. Here are a few "finer" details:

I just returned from a rendezvous at Yamhill, Oregon, where the gentle rain provoked not-so gentle oaths at many damned damp powder misfires. Yep, "keep your powder dry" is a must!

Even more so for flintlocks. As said, your flint, your frizzen, and your pan must be bone dry.

Most flintlockers use FFg (coarse granuals) black powder behind rifle and pistol ball; however, in the pan of serious shooters, only FFFFg, (fine granuals) are sprinkled--the best pan powder we can find these days (5Fg is now rare).

This priming powder is even more susceptible to moisture, and most flintlockers keep it in a special horn undercover. While hangfires (slow ignitions) and squibs (weak shots) are certainly possible from slightly damp powder, the only result I’ve ever witnessed from moisture is no ignition whatsoever.

Another term: "Flash in the pan" is an analogy for someone showy but ineffectual. The real thing is damp FFg in the pipe failing to ignite from dry FFFFg in the pan.

I hope you can use some of this in your story.

Saskatoonistan said:
Putting on my former ammunition tech hat on for a second ...

Black powder is extremely hygroscopic (it's a word, serious!) which means that it will actually draw moisture from the air so it absolutely must be stored in very dry conditions. Based on all my experience using black powder, even when it's slightly moist, you're probably going to get a misfire or it will dramatically affect its burn rate and therefore, the muzzle velocity of the projectile. Will you get more smoke than normal - no - but bear in mind black powder produces HUGE amounts of smoke and propellant gases when it's bone dry. Hope that helps.

Ok, wow. I was definitely not expecting to have 6 experts respond overnight. You guys are awesome. And maybe I should be a bit more precise as to what's going on.

This scenario is taking place in the late 18th century, aboard a frigate. They're using black powder that has been made using improperly prepared saltpeter, so it still contains small amounts of calcium nitrate (which is much, much more hygroscopic than potassium nitrate). So even though they've been keeping it stored away from the elements, the calcium nitrate in the powder still has absorbed moisture from the air - say, 10% calcium nitrate, mostly saturated from a 3 month voyage. I can vary the amounts, I'm just wondering if there's a point at which the black powder can still be usable, but tends to behave a little bit strangely.

As for the priming, the shooter will be using the napoleon method with ball and powder wrapped in a paper cylinder, and priming with a little bit of the powder that he used as the main charge. Frizzen, flint, and pan will be bone dry, only the powder is slightly damp. He has 5 minutes to execute two prisoners locked up in the hold, and his first shot is a misfire from very damp powder due to not having fired the pistol for several weeks. He still has some time before he has to go in swinging.

And tyty Chase for the terms hangfire and squib. I knew they were out there, but my own black powder experience is limited to a single shot. Also nice to know that damp powder wouldn't produce more smoke than usual, which is still a hell of a lot in an enclosed space.

Chase · Jun 24, 2010

Stanmiller said:
In my state we can't buy black powder without an FFL so have to use Pyrodex or other modern black powder equivalent . . .

In the late 1700s, the gatekeepers also tried to limit our access to powder. You could try smuggling in some inside the soles of your tennis shoes (just kidding, BATF).

Tsu Dho Nimh said:
None of the above:

If you re-prime on top of damp powder you still have damp powder!

My "Black Powder Bible" says you have to remove the ball, remove the wadding, dig out the main charge (which will have packed down real good because of the dampness), clean the firing mechanism and barrel, reload gun properly with dry powder and primer.

Too true, TDN. Kudos to you for the definitive answer to JayD's basic question.

Firing a flintlock pistol with damp powder

JayD

Recovering Lurker

johnnysannie

Stanmiller

Saskatoonistan

Still the wrong side of Saskatoon

WriteKnight

Arranger Of Disorder

Chase

It Takes All of Us to End Racism