First thing you need to think about is you will HAVE to change the bolt face if your going 223 And if I were to do this,I would make it a single shot...Cause your mag. isn't gonna work..As far as the recoil lug goes,you will get a ton of different answers about that..I have not noticed any difference in the builds I have done over the years...And as far as the Ackley Improved,my OWN opinion is it is a waste of money..All you gain is maybe 250 fps faster..You will need the dies for it..Like I said only my opinion...Some say it is a world of good and I know other who wish they had left it alone...If you want to go that route why not use what you have and make it a 243 AI then you can use your mag with it and not change the bolt any....Good luck with what ever you do...John