What are the specifics that a person looks for in a new barrel for a black powder cartridge rifle?

Manufacture?

Is there a difference in groove type and rate of twist?

what are you going to chamber it for?

Rich

perhaps a 45-70 or a 40-90 maybe. I have not really decided yet. This project is still in the thinking stage. I have a few questions before I can make a definitive statement on caliber or barrel.

Will a shilen or douglas barrel work work for a BPCR or do I need to look at a barrel designed specifically for the BPCR?

Do the lower pressure black powder cartridges shooting lead bullets need a slower twist than high powered smokeless rifles that shoot jacketed bullets?