I've loaded some more with both powders to try out again. I took the gun totally apart and gave it a cleaning and a half. I'm kind of hoping that the last time it was cleaned some fouling got left in the barrel. I think my next minor investment will be a bore light so I can actually look down the barrel and see if it's clean.
Now if I can somehow convince the boss that it would be in both of our best interests to go try these loads out during the daylight hours when he thinks I need to be working.