Much better groupings with this barrel.
I use it in my Echo 1 Stag arms m4.
I was having 2-3 feet groupings at about 150 feet, now they're about 6-8 inches.
quite easy to install, but youtube it or something unless you know how.
increases FPS by a bit (not discernible how much by eyes only)
super tight groupings
Rating: [5 of 5 Stars!]