[commando57]

I am new to AR’s and some things do not click. First, on gas systems, what does mid length and carbine length mean? How do you tell the difference between the two? How do you identify a gas piston rifle? Then there is barrel length, this part really does not compute, why does everyone order a barrel that is 11.5 inches long then add a fake suppressor that is 5 inches long to bring the OAL to a legal 16 inches or so? Why don’t they get a 16 inch barrel and enjoy the extra velocity? I have a AR-15 from Armalite that has a regular stock and a folding stock with 2 different buffer springs and tubes. Are they interchangeable?

[Constructor]

I have been wondering the same thing on a 11.5" barrel with a 5" flash, so I have no idea why they do that, A 14.5" barrel with a flash makes a little more sense if they want to keep the overall length down. I assume you are talking about rifle length and carbine length buffer springs and tubes, they are not interchangeable, short spring goes with short tube and collapsable stock. A carbine length gas system is apx 7" long, the rear of the gas block will be 7"+- down the barrel, A mid gas will be at 9"+-, A mid length gas system will delay the opening of the bolt and the cycling of the action, they can be a little easier on the system(bolt and cam pin mainly). The piston system has a piston in a cylinder around the gas block location(every system is different) and a rod replaces the gas tube.