If 5.7A-28 velocity is your thing the R50 is the right carbine for you. This side-folding tack driver gives you maximum speed accuracy and power downrange with its 16 inch threaded barrel and optic mounting option. Like many KelTecs the R50 is ideal for small game hunting bullseye shooting or just showing off for your friends at the range. R50 stands for Rifle - 50 Rounds in complementing contrast to the P50 the pistol version of the same platform. This carbine features a side-folding stock that rests nicely on either side of the grip when folded and a A 1/2 x 28 threaded - 16 inch barrel. It does come with some utility sights that are adjustable for windage and elevation however the R50 receiver offers over 7 inches of picatinny rail space up top for mounting just about any optic or accessory you like. 2 inches of rail space on the bottom is ideal for light and grip options. There's a QD sling cup just above the magazine release for mounting a single point sling and the AR style charging handle offers smooth manipulation.