Does anyone know if there is a #11 or Musket cap conversion kit for the Knight Long Range Hunter, in .50 cal?

No. But IIRC someone converted a Disc Elite to #11. It's the same thing since the parts are the same.

No but the Origonal Disc has a different type to hold a #11 cap, maybe Knight sells them for the Disc Extreme. Chap Gleason

You have to change bolts and breechplugs. The Extreme style disc isn't a true DISC, Dual Ignition System Concept. It'd be cheaper and easier to just find a used (or possiblly NIB) Disc Rifle. They're pretty cheap these days. Although in a state that requires #11 or Musket caps I don't know if they'd consider it a sealed ignition or not.

I have an original disc that uses the orange primer holders. I can buy some primers that hold a #11 cap. I thinkthey can be used over and over but not sure. What do you know about them Wolfhound? I have wondered about getting some of them.

I've never even seen one except in a catalog so I don't know anything about them. I believe the metal inserts are reusable but I don't know for sure. They seemed awfully expensive if they couldn't be reused.