Tippmann Arms Company M4-22 Pro, Semi-Automatic Pistol, AR, 22 LR, 11 Barrel, Composite MLOK Handguard, Matte Finish, Black, Pistol Tube, Front/Rear Flip Sights, 1 Magazine, 25 Rounds A101030 The M4-22 PRO Pistol is a premium .22 caliber semi-automatic AR styled pistol with aluminum upper and lower receivers and all the features of a true M4 pistol. The PRO Pistol features a 11 inch barrel, 9 inch Composite MLok handguard and weighs only 4.4 lbs.