The one on the right is my 14 year old son's S&W 15-22. It is a fun gun to shoot and very reliable, 25 round mags are readily availible. I have even seen 50 round drums for it,. but I haven't bought any yet. Most of your AR-15 accesories like grips, sites, ect. will fit right on it. Since this picture was taken, I have removed the front grip. My son decided that it was more accurate if he just gripped the quadrail directly.