Tippmann Arms Company M4-22 Pro Compact, Semi-Automatic Pistol, AR, 22 LR, 11 Barrel, A2 Birdcage Flash Hider, Matte Finish, Black, Free Float Composite M-LOK Handguard, Picatinny Rear Adapter, Front/Rear Flip Sights, 25 Rounds, 1 Magazine A101194 The M4-22 PRO Compact 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, Compact Bolt System, Rear Pic Rail Adapter and weighs only 4.1 lbs.