I have an AR Pistol in 5.7 with a super safety, folding stock, and optic installed. I also installed a heavier buffer and spring. Barrel is 8 1/2 inches. Comes with 4 full mags. One mag is 42 rounds, the other three are 30 rounds. Extra ammo as well. Shoots amazing, super reliable. With the super safety it will shoot a whole magazine full auto if you want. The folding stock is convenient, I can fit the gun in a small backpack with ease. And then when shooting I can fold the stock back out and extend it and it feels like a full rifle. Absolutely love this gun, just wanting to liquidate some of my possessions. I bought the gun new from Idaho Arms and Ammo in Meridian Idaho. Have all receipts.