I'm considering getting an entry level .223 AR 15 rifle soon (entry level meaning priced under $1000). I don't know much about the different companies making them other than S&W MP 15 and I hear Ruger makes one. I would appreciate input on some of the others that are available- their quality, reliability, etc. Also would like to know if any .223 can be adapted to shoot 22lr for target practice by changing the upper or lower or whatever you change to adapt them, or if only certainly rifles can be adapted to shoot both calibers. Thanks in advance