I would like to jump in here. I am currently shooting a BC in 45/70 and using black powder.
Here are my costs as close as I can figure - Graff FFFg at about $19 per lb. (bought 5 lb. at a time including shipping and hazmat fee). I am using 65 grains so that is about $0.18. I am using a 405 grain RNFP from Chey-Cast prelubed with BP lube at about $0.30 each. Add a Circle Fly 1/8" wad for $0.01 each. As for primers, your guess is as good as mine. I have not included the cost of brass.
With the BP lube, I fire 1 fouling round, then it doesn't get touched until I am done shooting. Accuracy is not impared because the BP lube keeps the fouling soft. I do have a jug of water with a squirt of dish soap to put the spent brass in. By the time I get home from the range, they have been agitated by the ride and all that is needed is a rinse off. I put them in the vibrator to shine them up, but that is not required.
Black powder fouling is not that corrosive, but is does draw moisture. I clean my BC by taking the barrel into the sink and washing it down with
really hot water and a couple of patches. The barrel is dry almost immediately due to the heat of the water. I use Baslitol after the wash for lubrication. I wipe down the reciever with Balistol, also. Petroleum based lubrication will react with the BP to form a nasty stuff that is really hard to clean up (Don't ask me how I know.

). I find this to be a really easy clean-up routine.
The thing that is hard to quantify is the WooHoo factor. I just have fun shooting this thing.
Chancy
