I converted my Disc over to the Extreme about two years ago.I found the best prices on the Orange Disc's at www.midsouthshooterssupply.com
I doubt if the orginal Disc's will ever be discontinued. The Red cone is superior to the orange Disc system.There are to many Disc rifles floating around using the orange disc's for them to be dropped from Knight's line.

Midsouth has 100 Orange Disc's for 6.39 their order number is 061-901107 40.00 Min order req.............

Ruger Redhawk