Any 209 primer with the words "Muzzleloader" on the packaging is a reduced power primer... made to minimize fowling with easy to set off powders (Black Powder, Pyrodex loose/pellets, 777 loose/pellets, white hots etc).
They don't tend to work very well with Blackhorn209. Blackhorn209 needs more heat to be reliable: Standard shotgun 209's or Magnum 209's are prescribed with BlackHorn209. (the directions on the bottle usually address this as well)
I blogged about it here if you want more details:
https://www.badgerridgeind.com/badgerden/different-209-primers-and-muzzleloading