I was reading an article by Jorge Amselle entitled "The AR-15, you don’t need one and they are too dangerous to own"
when I read this interesting paragraph.
That does not even include the fact that the AR is the single most versatile rifle available. It can be converted to a muzzle loader for black powder, a crossbow for archery hunting, an air rifle
, and can be adapted to fire over a dozen different rifle and pistol calibers. The design makes it easy to install optics and scopes, the collapsible stock allows the length to be adjusted so different statured shooters can comfortably use the same rifle. All of these features are why it is so popular.
I was aware that they can be configured for different calibers but the part that I have bolded threw me. Where does one get these conversion kits which can convert it to a black powder rifle, a crossbow, or an air rifle?