new barrel, new patches

[kartoffel]

I've been having trouble with the barrel on a new flintlock. It's a .50 cal with a "compromise" 1:48 twist rate and real deep square-cut rifling. The rifling and twist rate seem a bit overkill, but that's the barrel the gun came with so I figured I may as well shoot it and see.

Using 70 grains of FFg and .490" ball, 0.010" patches were completely burned through. Nothing left but blackened and frayed donuts of cotton. Would probably work fine with .495" ball, but I didn't have any.

Next, I picked up some patches labeled as 0.015" thick, only to find they were WAY too thick. Couldn't get a ball seated even by pounding on it. So, I tried doubling up my original 0.010" patches and found that it worked just fine! No more burn through. Patches didn't even cut until I increased the powder charge to 80 grains. Turns out the 10 thou patches were actually around 6 to 8, and the crappy 15 thou ones were more like 20.

I guess the moral of the story is never to trust the manufacturer when it comes to patch thickness. Mic the patches you shoot and learn what works best for you. If you don't have a micrometer, just stack up 100 patches evenly and measure with a ruler.

 

[arcticap]

I'm glad that you found a solution that worked. Some people use the wool wad bore buttons or card wads under the ball to act like a gas check and to help stop the hot gases from burning patches.

 

[kartoffel]

Maybe cotton balls would do the trick. My mind works in devious ways-- the local range just happens to be next door to a cotton field

 

[arcticap]

Cotton balls might work if you don't mind a few burning embers, and a little wadded up newspaper should too, although I've only used these and wadding in shotguns shooting shotloads though.