What would be a good reloading source for black powder express cartridges?

Are you asking where to purchase the necessary materials or a "how to" book or source of reloaded cartridges? Not sure the nature of the question.

Dutch

A reloading manual.

As a rule, if you're loading black powder, the right load is whatever you can cram in. ffG would be about the right grade. Or, are you looking for smokeless loads for BP pressures?

Graeme Wright's book, 2nd Ed., Shooting the British Double Rifle is a good source.
COTW has a lot of reliable load data for the standard BPE loads with FFg BP, and Cordite loads for the NFBP cartridges.

Use Ross Seyfrieds formulas for converting original BP charge to 40 to 46% of that weight in H4198 or IMR-4198 ... or Cordite to RL-15 by the 1.19 multiplier ... and do not forget the polyester fiber filler, and plenty of it.

I recently had a refresher at someone else's expense regarding the above, and the below:

RIP,

Thanks for the info.

Very interesting links. I see McGowen there. I know Harry. He custom built one rifle for me 30 years ago. I had him do a barrel for another a few years ago.

I happen to call him the day they arrived with the trucks to cart off all his machinery. I wish new owner all the best.

Pete

Good Ol' Harry!!! At a daring 76 years young, one of the last things he did before selling out to McGowen Precision Barrels, LLC, division of American Gun Holdings, was to revive the .395"-grooved barrel at my request. Harry deserves a special place in The Rifle Looney Hall of Fame.

Hooray for Harry McGowen!!!