Three of us braved the 90 degree temps and 80% humidity yesterday to shoot our woodswalk. We had a couple of problems. My powder horn kept clogging up about 5" from the spout. It was packed solid and no powder would flow. I had to cut a green twig and ream it loose, after which the powder flowed freely with no sign of any moisture. This happened 3 times after about 5 shots. I was using 2f Schuetzen.
Another guy had several misfires with a loaded rifle. After trying 3 caps, we would remove the nipple and dribble some 4f into the flash channel, after which it would fire. The only thing I noticed was that he ran out of caps, which had been CCI magnums and I gave him some regular CCI caps. Evidently they didn't have enough flame to reach the powder.
As it was, we had trouble locating many of the targets because the undergrowth had sprung up to the point that it obscured them. We had last shot the walk in May. We shoot from one side of a ravine and the targets are on other side. The brush in the ravine has grown to the point that it hides the target. The property owner had the place selectively logged a couple of years ago and this was after we had set up the walk. Opening up various areas has allowed the undergrowth to spring up. I suppose now we'll have to wait until fall before we shoot again.