Still looking for a Knight Disc but I put the word out on another forum and a guy emailed me back this:
"TMAN, I have a khight disc that uses 209 shotgun primers. It has a 50 cal 22" stainless barrel with a black composition stock and is a bolt action I hAVE NO IDEA WHAT MODEL IT IS. iF you can help me identify it as to what you want we can talk $.I bought it new 15 0r so years ago.Any interest let me know"
Any idea what model he is talking about and the value? Could I change it to a #11 cap?
thanks
It is probably a Knight Original DISC...

It will probably come ready to shoot shotgun primers that you install in an Orange plastic jacket, and they also made a plastic jacket that you could install a #11 in - but it would not be legal for the northwest as the cap is not exposed.
To make the conversion from the Orange jackets to #11 or Musket that you could use in Washington you would have to purchase a Western Kit from Knight, remove the firing pin assembly from the the old bolt and install in the new Western Bolt with a the new breech plug.
The stock is also kinda odd... it is great for open sights but to low for a scope which shouldn't be a problem.
Here is another one listed on Gun Broker..
http://www.gunbroker.com/Auction/ViewItem.aspx?Item=282096004The Original DISC was the fore runner to the Knight DISC Extreme and Elite