Here is a pic of a sample group I fired using a GM 20" gov profile 1:8 barrel.
10 shots @100 yrds using 55Vmax in LC brass.RL15 and CCI primers.
Note: It does better with factory TAP ammo. Especially the 60gr. TAP.
Here’s a pic of the rifle in question. It’s nothing fancy (the glass is a cheap 4-16x50 that has since been decommisioned 
There is a lot of WTF? in this thread… seriously, relegating GM barrels to the junk bin because a company you don’t like uses them?
I will say right up front that the guy that runs GM is a good friend… but I can also say that they have made a metric shitload of AR barrels for a LOT of different companies, and while some bottom rung company may use them, guess what, GM also makes the barrels for some of the top names that people get all gooey about.
Green Mountain makes a very good barrel…
WTF ever happened to people staying in their lanes on this board?
It used to be if you posted “I have no experience with… BUT am going to post some BS opinion anyways” you got your ass handed to you. I guess that went the way of the dodo when the great migration of the TOS to m4carbine.net occurred.
From what I have read Green Mountain supplies barrels to Colt when Colt cannot meet production volume.
There is another thread on this board in which people who actually own and shoot Green Mountain barrels share their results. I the OP check that thread out.