Geno:
The grease cookie, or alternative bullet-lube/fouling-softening set-up within the cartridge, is critical in loading BP cartridges for accuracy. If you haven't researched this, Mathews has produced a number of inexpensive booklets on the topic, and Graeme Wright's chapter on loading BP Express cartridges gives a few hints. Without lube in there somewhere, you will be unlikely to fire 10 shots without loosing accuracy, perhaps by a 1/2-yard (!), because the hard crusted fouling from the first few shots damages the lead bullet on subsequent shots. All brands of modern black powder are significantly less moist-burning than originals like Curtis & Harvey etc.
If you already know this, please disregard. Also, others have found that using a drop-tube to introduce black powder into the case reduces accuracy for some reason, but not by half a yard. I think that was reported by Sherman Bell, finding out for himself once again.
Hope your next range session sorts out the problems.
