I have been looking for Remington 209-4 primers since last muzzle loading season!
All of the stores around here report that the 209-4 is discontinued!
Yesterday, I called to the Remington plant and the guy I spoke with said that the 209-4 primers have in fact been discontinued!
He said that they have developed a new primer for in-line Muzzle Loaders, dubbed the 209-ML
He wouldn't say whether or not the 209-ML was suitable for loading 410 shells, said it was a liability thing!
He said they have lots of them ready for shipment, and they just got D.O.T. approval for shipping! So, they should be in stores within a couple of weeks!