Nothing of your load sounded unreasonable. I will say that a full case load of BP can flatten a primer, as the primer is firing into a solid mass as opposed to the air space of a smokeless load. The chamber might have had some fouling in it, though I suspect the RB might not have generated enough back pressure to seal the case, allowing fouling to dirty the chamber, making extraction more difficult.
I also suspect part of the reason for the .44 magnum impression is the impressive fireball and blast from that load, with a portion of the powder finishing it's burn at the muzzle.
Load up the rest and enjoy them.