If you absolutely have to have a .223 WSSM, it could be done. You'll have to open up the bolt face and extractor. You'll probably not be able to get it to feed from the magazine, but you can use a Score High single shot follower or something similar. If it were mine, I would go for a 22-250 Ackley Imp or a regular Swift. You'll get the same performance, but should be able to make it a repeater and won't have to cut on the bolt face.