I shoot 209's in my elite cause thats the breech plug that came with it. But in my knight MK, I bought the conversion kit for 209's and found a accuracy penalty using them. I was getting 2"-3" groups at 100 yards with No11 and that opened up consistently to 4-5" with winchesters.

Reason I changed was I wanted to shoot pellets and wiht No11, I had a misfire on a deer. Which I ended up going back to loose anyway.

My elite shoots the 209's well, but you have to use a tight fitting sabot. Really 209 is way too hot. But you a almost assured a fire, when you pull that trigger.