I have a Super Single Six that I have been having some minor trouble wih. It gets lead built up around the ejector rod opening. I have trouble moving the rod for the first casing or two and then it moves okay. The next time I run a cylinder full same thing happens. If it is freshly cleaned I get about 40 rounds or so through it before this happens. If I take the cylinder out and clean off the lead I only get about 10-15 rounds before it builds up enough again to cause a problem. This is with 22lr bullets not the 22 mag. Any suggestions?