Might find that a problem. Better to have the outfitter supply it for you, I would expect.
Last I heard, was that the only carrier allowed to carry black powder in Canada, Purolator, refused to do it.
Now, we've had black powder shooters come shooting here every year to rendezvous and hunting as well from the States, however these people normally drive and as far as I know, have had no difficulty at the border unless they had handguns of any sort.
I suggest you contact the Firearms centre and ask.
https://www.rcmp-grc.gc.ca/en/firearms/contact-the-canadian-firearms-programFound this: Appears driving is fine. The Airlines might have trouble with it.
Exemption of Certain Explosives
[SOR/2018-231, s. 21]
Marginal note:List of explosives
190 (1) A carrier or driver is not subject to the requirements of sections 191 to 203.1 if they transport
(a) no more than 12 kg of an explosive with the number UN 0027, BLACK POWDER (GUNPOWDER) or UN 0028, BLACK POWDER (GUNPOWDER) COMPRESSED;