I had been kicking around the idea for over 4 years now, and just put my idea to the test yesterday. I have mentioned this before, a few years ago, hoping someone already had what was needed to test this without me having to buy before try. This conversion would be nice for the States that do not allow 209 primers. You do not need to change breech plugs, and you still use your 209 carriers, but no 209's.
All you need to do is buy a pack of the Knight ORIGINAL orange DISC's with the #11 nipples included. Or better yet, find a buddy that owns an original Knight DISC rifle that does not shoot the #11's and take his #11 nipples. I bought a 25 pack of orange DISC's with 10 #11 nipples included. The orange DISC's are worthless to me, but the #11 nipples are priceless. You will not need to modify anything, these fit and work perfectly. Take the #11 nipple and insert it into the business end of the 209 carrier.....push a #11 cap on nipple inside the carrier.....insert carrier into breech plug.....close action.....point in safe direction.....cock hammer.....pull trigger.....BANG!!!
I have only fired caps without a powder charge, but this is going to work. I fired 6 Remington #11 caps, then 6 RWS 1075 Plus (#11) caps in a row. Went bang every time! I will be testing this out with actual powder loads hopefully during the week, or this weekend. I did have some residue from the caps, but if I had fired 12 209's in a row, I would have had a horrible mess. Hard to say how much mess will be there when firing actual powder loads, but I honestly don't think it will be as bad as using 209's.
Just thought that someone would be interested, and if you have a buddy with and original DISC, you could try it for nothing. I paid $15 for the 25 DISC's w/#11 nipples. I got the ones with the stainless steel nipples, but they also had them in black. I did examine the nipple and my firing pin after this experiment, while only 12 strikes, both still looked like new. I can't imagine ever wearing out the firing pin, but if you did, all you need to do is punch out the top receiver pin and insert a new one. Easy as pie!
Knight Percussion D.I.S.C.'s #901106.