The "youth" models and the "adult" models are EXACTLY the same.....except that the length of pull is 1" shorter on the youth models...and the barrel is usually 20" in length (I'm not sure about the .223). It is absolutely no problem to change to the "adult" stock. I have had a couple of "youth" model 700s, which I chose specifically for the 20" barrel. I simply changed the stocks (to aftermarket ones)....which I would have done anyway.