Help with build- barrel, gas tube, etc

[Usafa71]

Finally jumping into the Grendel rabbit hole, and would appreciate input from the brain trust.

I am left handed, and have a Stag LH in 5.56. I have another left hand upper and Grendel BCG enroute from Stag, and now need to think about barrels, etc. Initially I plan on just building the upper to go on the Stag lower, but will eventually finish a complete build.

I am looking for an 18” barrel, as a compromise between the ballistics of a longer (20” or greater) barrel, and the handiness and maneuverability of the 16”. I am looking for a mid weight rifle, possibly for hunting, but mostly will be used for targets/ steel at 200-500 yds. Plan on 110-130 gr bullets almost exclusively. Thinking a heavier barrel(for accuracy) but fluted for weight savings. Seems like 1 in 8 twist is the way to go.

So would like recommendations from the brain trust as to who makes a good barrel. I would like below MOA accuracy(on the days that I can shoot that well). I will be reloading once I get brass and dies. Don’t want to spend a fortune, but want a good barrel.

Gas length- any advantage to mid-length vs rifle length vs carbine length?

Gas block- any real advantage to an adjustable gas block(have one on the 5.56, but have not had much chance to adjust it once I got it working). If you have an adjustable gas block, do you adjust it for temperature, etc, or just leave it once you have it working? Do they usually stay adjusted, or do you have to play with them like the carburetors on a 60’s era Austin Healy or MG(yes, I am that old!).

Any suggestions or opinions on barrel manufacturers/ barrel length, gas block, gas tube length, or any other things I need to consider, would be appreciated. I have searched the forum and found good info on Faxon, Precision Firearms, Lilja, Wilson Combat, and others, but would like any other input available.

Thank you for your input.

[Bigs28]

I would get my barrel from precision firearms. My 12" krieger shoots 8 shot 0.6 moa groups. I don't see the point in an 18" barrel other then "because that's what i want". A 16" will hit steel out to 500 np and the extra 2" isn't going to change much.

If your going to shoot suppressed i would go with some sort of adjustable gas. Either with the block or a bootleg adjustable bolt carrier. To me the cost of an adjustable gas block makes it a no brainer to get anyway.

[Usafa71]

Bigs28- thanks for the input. I will definitely consider the 16” barrel, since I doubt the extra 2” will make much difference ballistically, especially in a cartridge that works so well in a 12” barrel!
Not much reason not to get an adjustable gas block. Don’t plan on going suppressed, but that may change.

[VASCAR2]

Before making decisions I like to know the facts and specifications. I generally shoot bullets 123 grains or less in the 6.5 Grendel. I think an 18” 6.5 Grendel hits the sweet spot for the 6.5 Grendel if you only ever anticipate having one. Here are velocities a Friend and I got using a Magnettospeed chronograph a few years ago on a 70 degree day.

The which barrel question routinely come up on this forum and it really boils down to how much accuracy you want and what your willing to pay. Precision Firearms, Lilja, Criterion, JP, Wilson Combat, Rainier Ultra Match, Odin plus other custom barrel makers get good reviews. The Monster logo barrels sold by BFT on SixFiveOutfitters get good reviews as well as Aero Precision, Faxon for rack grade barrels.

123 grain A-Max Hornady

12” 2265 (123 grain ELD-M)

16" 2419

18" 2464

20" 2505

24" 2568

123 Grain SST Hornady

12” 2277

16" 2430

18" 2493

20" 2511

24" 2583

Hand Load 123 Grain Nosler CC, 31.0 grains CFE223, CCI 450

16" 2449

18" 2471

20" 2526

24" 2619

[grayfox]

The only bullet over 123 that I would consider, hunting wise, is the 129 nosler ablr.
100-115 in lead free, 120-123 class for cup/core, hunting wise.
But I bang my steel with bigger cartridges so there is that. These are my choosins'.

Personally I have settled on most of my barrels as 20", I didn't like the blast and kick from the 16" that I had, and 20" has nodes that I can easily find.

Like said above, the barrel price depends on what you want to spend -- wait a minute!!! with that cheaper barrel you wind up spending more $$ on bullets, loads and gas for trips to the range. So your "barrel cost" as it were, is the same or higher for that cheeper barrel. I know I have gone that route in the past.
Barrel, trigger, scope/optics. These are the money parts. the rest just hold stuff together.

I suggest a lilja if you want to get it right away, they pretty much have barrels on their webite. Or if you can wait, then precision firearms...
Longer delivery times for krieger/bartlein but they are darn fine barrels. Others are decent to be sure but a step down from these ones.
I got a lilja 20", the 740 model (among others lol), but I don't plan on hiking over hill and dale like I did in my younger years lol. A 20" rig weighs about 9.5 lbs if you build it out right.
You can always add an adjustable gas block later, so far I have not needed it much for the grr even though I have a couple agb's on the shelf.

If you do go 18" then definitely get the rifle length gas. The shorter gas length has had troubles with getting the gas right. 18 or 20, rifle length for sure.

[Usafa71]

Vascar2 and grayfox- thank you both for the input! Still leaning toward the 18” barrel, if only for the full-length gas system. While I don’t want to “waste” money on a barrel, I do find that quality products are usually the least expensive in the long term.

Since scopes were mentioned, does anyone know of a scope for the Grendel with a BDC specifically for the 123-129 gr bullets?

[VASCAR2]

The 6.5 Grendel trajectory is very similar to 308/7.62x51 and Primary Arms carry a few scopes with reticle designed to work with both cartridges. I have no personal experience with these particular scopes but have had positive experiences purchasing products from Primary Arms in the past. Here is a link to a scope that might be appropriate for an 18”-20” 6.5 Grendel.


https://www.primaryarms.com/primary-arms...08-reticle

[Usafa71]

VASCAR2- thank you. I have experience with Primary Arms, and their scopes, all positive. Will have to compare 308vs 6.5G trajectories, but at least I have a starting point.

[garikfox]

Aero Precision 18". Supposedly Aero Precision makes all the parts for Daniel Defense. Can't go wrong with that

[Bonas]

I got a Grendel Douglas-blanked barrel from Compass Lake Engineering that shoots very well. .6 to .8 moa groups are commonplace. They delivered right when they said they would, with excellent follow-up and communication along the way.

The big jump in blanks is from button-rifled to cut-rifled. Kreiger, Bartlein, and Satern are the only cut-rifled Gendel blanks I know of.

Compass Lake has been known as among the very best barrel finishers for decades.

[Bonas]

Aero Precision 18". Supposedly Aero Precision makes all the parts for Daniel Defense. Can't go wrong with that

Aero does not make all of Daniel Defense's parts. I don't think they make any, in fact. Daniel Defense has their own cold hammer forge. They forge their own barrels. I have nothing against Aero. I have plenty of Aero upper receivers, in fact. However, Aero is a mid-range producer. Ballistic Advantage makes Aero's barrels. I've also got several BA barrels. They're also a mid-range product. Aero bought BA a few years back.

[garikfox]

Oh okay good to know thanks