Here are a couple of pictures of my SBR AR-15 in 5.56. I also have a 22 LR upper that will fit on here also.

The barrel on the 556 is 11.5inches I believe it is the same on the 22.

One of the great things about the AR it is very modular. With the lower being the firearm all I have to do is pay for one tax stamp for the SBR and then I can run multiple calibers and various length uppers on that lower.