I'm new here ... not sure I know how to search yet as well as navigate the forums, so bear with me. I'm trying to building my first AR platform. I'm leaning towards, but not committed to, building an AR in 6.5 Grendel with a an approximately 9.5 to 11.5 inch barrel with a 9" suppressor on it. I'm curious what can I expect for precision out to 600 yards (target)  and 300 yards (realistic hunting). Anyone got any real world results?

The Alexander Arms 11.5” barrels generally are good shooters so most reports are 1-1.5 MOA with preferred ammo.  I find pistol Ar-15’s more difficult to shoot.   The Nosler 129 grain Accu Bond Long Range expands down to 1300 FPS and has proven very popular in the Ar-15 pistols chambered in 6.5 Grendel.   Lilja has gotten great reviews on their 6.5 Grendel barrels.  Most short 6.5 Grendel barrels on the market are 12”-12.5”.   I have a 12” PSA and a 12” Green Mountain Monster logo 6.5 Grendel barrels.    A quality barrel should shoot good regardless of length.  If you want guaranteed  accuracy get the Lilja or other high end barrel.  It is generally cheaper in the end to get a quality barrel as wasted ammo and range time usually off set the cost if you get a cheap barrel that does not shoot to your expectations.

Thanks for the info. The barrel length I referenced is just some that I had found while searching online. So, 12-12.5" should be fine as well. And thanks for the manufacturers recommendation. That was probably going to be my next question.

Well I dont see that barrel on Lilja's website and the only reference I could find online was a special group buy at one time. :/

I suggest you call Lilja and see if they will sell what you want.  If not Craddock Precision or Precision Firearms can produce quality 6.5 Grendel barrels but there are significant wait times for delivery.


Here are some velocities Mark from Precision Firearms posted on short 6.5 Grendel barrels.  This might give you an idea what length barrel you want to purchase.   You might buy a AA, Faxon, BA, PSA or Monster Logo Green Mountain barrel.   You could see if you like the platform while you wait on a custom barrel then sell the cheaper barrel/upper after you receive the custom barrel.


Precision firearms short barrel velocity.

7.5 Bartlien at 100 Yards. Groups averaged 1.5 Inches 2000 FPS 123 Match King
8.5 Bartlien at 100 Yards. Groups Averaged 1.4 Inches 2100 FPS 123 Match King
10.5 Bartlien at 100 Yards. Groups averaged .9 Inches 2200 FPS 123 Match King
12.5 Lilja Blank Chambered by PF at 100 Yards. Groups .75 2300 FPS 123 Match King
14.5 Lilja Blank Chambered by PF at 100 Yards. Groups .5 2350 FPS 123 Match King
14.5 Krieger at 100 Yards. Groups averaged .38 2375 FPS 123 MatchKing

You are going to lose velocity for every inch you lop off so keep that in mind concerning twist.  You will need a faster twist with a shorter barrel to get the RPM's needed to stabilize a bullet at distance.  By the same token your trajectory arc will increase so your range estimation will be more critical.