Originally Posted by moneymaker17
sorry for the missunderstanding, i want to buy an ar-15, how ever i dont know what i want to shoot out of it.
i was asking what would be the best caliber for the gun/ for me to shoot
Give us a little more to work with, such as what kind of shooting do you intend to do? As has been stated the AR was engineered and designed to shoot the 5.56/.223 caliber round but I would hesitate to use that much energy for home defense. Do you want to use it for HD, plinking, target shooting, hunting, or general SHTF situations?
You may find that instead of putting $1200 or so into an AR with a 9mm upper you can get a 12ga shotty for HD, a purpose built .22lr AR or a 9mm Hi-Point carbine for plinking AND a 9mm handgun for CCW, all for the same money.