Are flintlocks reliable when it’s raining?
IMHO
Yes
And there’s many ways of keeping your powder dry.
Which is a must do.
I’ve only shot flintlocks for around 15 years now so I’m no expert by any means.
However I’ve shot with a lot of Guys that’s shot them for 40 + years .. and I watched their moves.
First I think a cow’s knee is a great idea and useful tool, especially if sitting for long periods in damp environments..(Deer Hunting)
By damp I mean fog, rain , snow and humidity. All will cause problems if not addressed.
What I’ve found is as long as your lock is clean / un fouled , stays covered and protected from water I will shoot.
Once the gun has been fired I’ve found it best to wipe the pan & flint with a dry rag..
Keep it in your pocket or shooting bag.
But keep it dry as possible..
Once the gun has been fired I don’t re prime until the next shot presents itself.
Fouling is what draws the moisture turning pan powder too black slush..
You’ll lose a few squirrels by waiting possibly, but the more you do it the easier it’ll become.
Keeping the lock under your coat is another good suggestion… whatever you can do to keep the lock dry helps. Barrel down…
I carry a small bottle (Cracker Barrel Syrup) filled with alcohol in my bag just Incase it’s needed.
Here’s a couple cows knees I’ve used with success. All are saturated with bees wax inside &out.
On woods walks I simply keep the lock under my coat until I’m ready to shoot.
I then wipe the pan one last time …prime, cock , aim and fire!
During a rainy woods walk a couple years ago I was able too fire 28 of 30 shots required without any issues.
The other 2 failed to fire due to a water drop falling of the brim of my hat directly onto my frizzen/ pan about the time the hammer fell…
Saved by the alcohol!
I failed too mention I mostly prime with ffffg..
But have used fffg in a pinch.
ffffg does tend too plug those push primers quicker when the pans been fouled..