What do you know about the M4 Carbine? The M4 Carbine is a 5.56 x 45mm Caliber Rifle. It has a maximum range of 600 meters. By Task & Purpose | Published Apr 28, 2020 9:07 PM The Gear Locker Reviews SHARE The M4 Carbine is a 5.56 x 45mm Caliber Rifle. It has a maximum range of 600 meters. Task & Purpose air force carbine gun... m4 m4 carbine MORE TO READ RELATED The Gear List: Blade HQ is offering up to 65 percent off knives right now Save big bucks on trendsetters and familiar favorites. READ NOW RELATED The Gear List: Must-have Seiko watch deals on Amazon Shut up and take my money! RELATED The best paracord bracelets for your everyday carry Be prepared and stylish with these paracord bracelets.