I have two Apex .50 caliber muzzleloaders and have decided to sell one of the them. The one I'm selling has been nitride treated. Here are some pictures:
https://postimg.cc/gallery/cWHLHvdOne picture shows the rifle wearing a Bushnell Trophy 3x9 with 250 DOA reticle in CVA Durasight mount.
$650 shipped to your dealer (must accept from individual) without scope/mount. Add $80 to include scope/mount.
I must add that the breech plug was apparently not given the nitride treatment (it's a BH209 plug) but was also made to match the black finish. I don't know what was used. The bore was also not nitrided.
picture shows two tiny dings in finish.
I would also consider a .45 caliber Apex muzzleloader in trade.