Believe it or not there are people that do it and even kits made for it: http://www.brassworldeshop.com/sharpshooter22rimfirereloadingkits22lr22magreloader.aspx
I had the idea of pulling the bullets from loaded factory ammo and experimenting with heavier .223 jacketed bullets, even going as high as 69 gr or heavier to try and work up a subsonic load that would still cycle the CMR. Then I checked the twist rate on the CMR, and there goes that idea. 1 in 14! I'm surprised even the 50gr rounds stabilize. Would be great if I could custom order a 1/9 or 1/8 twist barrel.
I had the idea of pulling the bullets from loaded factory ammo and experimenting with heavier .223 jacketed bullets, even going as high as 69 gr or heavier to try and work up a subsonic load that would still cycle the CMR. Then I checked the twist rate on the CMR, and there goes that idea. 1 in 14! I'm surprised even the 50gr rounds stabilize. Would be great if I could custom order a 1/9 or 1/8 twist barrel.