My Knight Disc likes the 300gr Barnes Expanders with 100grs FFg...or the 250 Shockwaves with 90 grains Pyrodes...I usually reuse the discs 3-4 times...found that the Winchester 209s pop out of the disc easier than the CCIs (after shooting)..

I love the Disc rifles...its easy to pop the discs in or out...really think Knight screwed up when they discontinued...a buddy converted and says its hard to get the 209s into the disc...he finally bought a tool to help...