Alcan made some brass hulls for the Remington size 57 primer, which unless you have a supply on hand will be very hard to find today. The vast majority of their brass hulls however were made for a 6.45mm Berdan primer. This primer is .254" in diameter or larger than a 209 primer. The Berdan primer was suitable only for black & bulk or easy igniting dense smokeless as Red Dot.
An old Lyman manual recommended for their use with progressive powders to drill through the primer pocket with an undersize drill from inside the case & C'Sink the pocket till a 209 size primer would press in flush.
I have never tried this but Lyman did recommend it. Would also be a possibility should anyone have any of the early Berdan Mag-Tech brass.
Should be no big deal though to fit a single stage loader to prime with the pistol primers of current Mag-tech brass, which would be best all around for using the all-brass shells.
