Rifle Length Gas System Barrel Length

[7.62mm]

What is the shortest you can get with an AR barrel that has a rifle length gas system, and have it function reliably?

 

[A.T.R.]

16.5".


DI or Piston will also come into play.

 

[7.62mm]

It will be a DI.

 

[jakester]

Many many years ago I remember reading in magazine about a test in where 20" Sp1 barrels (in the U.S. of course) being chopped to 16.5" and functioning perfectly. They did not even require enlarging the gas port diameter. Here in Canada we can chop an 20" AR barrel to 18.6" without trouble, I know of a gunsmith who has done it many times. Works just fine, and yes the 1.5" reduction does actually make it a bit handier.