28" Satern Liberty Upper - Yea or Nay?

[MegaHurtz]

Hola all, from a jarhead that turned another year older yesterday.

I just started a franken 6.5G build and am considering a non-fluted 28" 6.5G upper from Satern/Liberty. I see a lot of dialog herein surrounding SBRs & 16"/18"/20"/22"/24" Grendels, but little to nothing on the 28" product from Satern's Liberty Barrels Inc. subsidiary.

My indended use is to enter the world of owning a longer-range target/plinking/fun/bragging-rights weapon (and possibly use as a supplement to my 16" SHTF/HD 5.56 home-brew carbine). I am a big boy and am not afraid of the extra weight of those inches of steel hanging out there on that upper, and appreciate that its not likely to be compatible with longer periods of carriage, especially in any environ other that open high-desert. Swinging it around inside the house will be pretty comical to observe, I suspect.

All of the lower's items are on order - went with a full length rifle buffer kit, Luth-AR MBS1, CTK pic rail & Monopod for the stock, Larue grip & MBT-2S two-stage trigger group, anti-walk pins, and tension screw. I also got an accu wedge just to see if it is worth the plastic/rubber it is comprised of. With the lower I just received (a Sota Arms unit), and a generic lower parts kit, I should be all set on the bottom half, I perceive. 400 rds of new-condition Hornady 123gr HPBT is enroute along with 2ea 10rd and 1ea 26rd C Products 6.5G mags (and the interface for my MagnetoSpeed chronograph to xfer data to muh phone).

Anyways, i am hoping that someone can offer learned opinions and feedback on the Satern Overwatch 28" 6.5G upper, please. TIA.

S/F

-MHz

[VASCAR2]

There is only one forum member to my knowledge with a 28 inch 6.5 Grendel AR-15. A 28 inch 6.5 Grendel can create it’s own challenges with a rifle length gas system. The velocity gain over 24 inch is pretty minimal and I personally wouldn’t go longer than a 24 inch AR-15. The heart of any 6.5 Grendel is the barrel and for shooting long distances I want the best quality barrel I can afford. Here is a graph showing the potential for velocity relative barrel length.



A Friend and I chronographed a 16, 18, 20 and 24 inch barrels on the same day with a magnetto speed chronograph. Look at the difference between the 20 inch and 24 inch 6.5 Grendel barrels. The gain will be much less per inch over 24 inches due to the small 6.5 Grendel case capacity.


Here is a list of the tested ammo by average velocity for each barrel length.

120 Grain HP BT PPU

16" 2392

18" 2455

20" 2480

24" 2559

110 grain FMJ PPU

16" 2510

18" 2570

20" 2614

24" 2683

123 grain A-Max Hornady

16" 2419

18" 2464

20" 2505

24" 2568

123 Grain SST Hornady

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

100 Grain FMJ Wolf

16" 2507

18" 2571

20" 2615

24" 2695

Hand Load 107 Grain SMK 28.5 IMR8208XBR, CCI 41 Hornady cases.

20" 2658

24" 2729

Here is the difference between the 18? barrel compared to the shorter 16? barrel which was slower with every load.

120 grain PPU HP BT

63 FPS difference

110 grain PPU FMJ

60 FPS difference

123 grain A-Max

45 FPS difference

123 grain SST

63 FPS difference

Hand load 123 grain Nosler CC

27 FPS difference

Wolf 100 grain FMJ Steel cased

64 FPS difference


Difference between 20? and 18? barrel 6.5 Grendel

120 grain PPU HP BT

25 FPS difference

110 grain PPU FMJ

44 FPS

123 grain A-Max

41 FPS difference

123 grain SST

18 FPS

Hand load 123 grain Nosler CC

55 FPS difference

Wolf 100 grain FMJ Steel Cased

44 FPS difference

[grayfox]

Roger on Vascar's post. Instead of a 28" whatever barrel, get quality 20-24" like lilja, or one from Precision Firearms (a vendor on here), or a Criterion 22" to save just a bit on costs. In addition once you get beyond about 22" the RLGS starts to cause you issues, I've heard of a few R+2 gas systems but now you're talking beyond standard...

Also, talking long range means also talking accuracy so use some of your budget on a useable chrono like magnetospeed or lab radar. High Speed+ inaccuracy=frustration and Mega costs. Nice speed+ accuracy = braggin' rights. You can't get there without a chrono.

Finally, the Hornady Hpbt's (probably the 123 Black ammo, no?) will give you some breakin plus brass, but if you want to start stretching legs get some 120 Sierra MK's and proper powders. They are more suited to starting an accuracy journey in opinion of lots of shooters on here. The 123 SST's, although I like them, don't always like everybody's barrel so if you want to try them or not, up to you of course.

Happy Birthday USMC from a Navy guy who's also getting older...!

[MegaHurtz]

There is only one forum member to my knowledge with a 28 inch 6.5 Grendel AR-15. A 28 inch 6.5 Grendel can create it?s own challenges with a rifle length gas system. The velocity gain over 24 inch is pretty minimal and I personally wouldn?t go longer than a 24 inch AR-15. The heart of any 6.5 Grendel is the barrel and for shooting long distances I want the best quality barrel I can afford. Here is a graph showing the potential for velocity relative barrel length...

Here is a list of the tested ammo by average velocity for each barrel length...

In a few weeks, you can up that # to 2.

@ ZDT last night, I fell victim to a genuine impatience for continued shopping and an admitted need for instant gratification in light of not finding other complete uppers that struck the right chords with me. I went with the non-fluted so it could be cut down and rethreaded moar easily if I ultimately end up being unhappy with the hasty decision I made. They are cerakoting it for $18. I desire an all-black livery. Will be in hand in 3-ish weeks.

You and your buddy must have had a ton of fun throwing that much lead at paper that day - because science - Kudos!

Thank you for your time and effort. It is genuinely appreciated.

Roger on Vascar's post. Instead of a 28" whatever barrel, get quality 20-24" like lilja, or one from Precision Firearms (a vendor on here), or a Criterion 22" to save just a bit on costs. In addition once you get beyond about 22" the RLGS starts to cause you issues, I've heard of a few R+2 gas systems but now you're talking beyond standard...

Also, talking long range means also talking accuracy so use some of your budget on a useable chrono like magnetospeed or lab radar. High Speed+ inaccuracy=frustration and Mega costs. Nice speed+ accuracy = braggin' rights. You can't get there without a chrono.

Finally, the Hornady Hpbt's (probably the 123 Black ammo, no?) will give you some breakin plus brass, but if you want to start stretching legs get some 120 Sierra MK's and proper powders. They are more suited to starting an accuracy journey in opinion of lots of shooters on here. The 123 SST's, although I like them, don't always like everybody's barrel so if you want to try them or not, up to you of course.

Happy Birthday USMC from a Navy guy who's also getting older...!

Thank you for your service, Kind Sir.

Yep, I've a MagnetoSpeed chrono. Will have the adapter in hand in a couple of days, enabling importing numbers into Excel and geeking a bit on the data. A radar would be nice, and may be on my list at some point. However, I need to invest some sweaty equity in these endeavors, until I am sure having same will be worth the capital outlay.

The ammo is the Hornady American Gunner variety. I got it so I could break in the bbl and have once-shot reloading brass, once I am ready to traverse those paths. Until then, I'll endeavor to find a factory ammo setup that the bbl likes. We'll see...

Thanks for the time and effort in responding. It is very much appreciated.

[Lemonaid]

I ditched the accuwedge after it somehow got loose and blocked the trigger. YMMV

[MegaHurtz]

I ditched the accuwedge after it somehow got loose and blocked the trigger. YMMV

Doh!

Good to know. Thanks.

-MHz

[meatsweats]

Make sure to get a quality adjustable gas block. You will most certainly need it.
MS

[A5BLASTER]

I ditched the accuwedge after it somehow got loose and blocked the trigger. YMMV

Not sure how that would be possible to do. It's trapped behind and under the rear take down pin.

[Lemonaid]

Not sure how that would be possible to do. It's trapped behind and under the rear take down pin.

Murphy's law was invoked!

[MegaHurtz]

Make sure to get a quality adjustable gas block. You will most certainly need it.
MS

Yeah, noted. I talked with Ms. Maranda there and she was adamant that an adjustable block is not recommended.

She did volunteer that replacing the GB would not void the barrel warranty should I choose to do so anyway.

But, I can see the value in having one, especially when I start to traverse down the path of developing loads for this setup.

Thanks.

-MHz

[grayfox]

At 28" you might not need an adjustable, to be fair. however, if you do want some adjustment Ihave a Bootleg adjustable bcg for sale in the for sale section, that way you can adjust w/o messing with a gb... lil screwdriver twist right at the ejection port.

[another caliber]

I disagree. Any adjustable part on your rifle is just going to cause trouble. If your ammo doesn't work with a standard gas block and standard buffer spring and standard buffer then YOU are doing something wrong or outside the norm. Or, maybe, your rifle isn't first rate.

I've shot 100's of highpower rifle matches and I can only say that anything you need to adjust is likely to be wrong. I hate having to adjust my sling but I have a well developed card on what to do. It probably cost me several matches and $100's to get that card right and on a service rifle it would have been much cheaper since there are fewer options. Adjustable stocks are very expensive as there are way too many options: cheek riser height, length, height of butt stock, cant of butt stock...I did just as well with an A2 stock with no adjustments but I couldn't resist so I have an adjustable stock.

I've never had an adjustable trigger. I've seen too many people playing with their triggers when they should have been dry firing. I use CMC two stage triggers that are not adjustable and I'm perfectly happy to not be able to make any adjustments to the trigger although I do make adjustments to my grip and trigger pull when I realize I'm not doing it right while dry firing as I wait for the "targets up" call.

[A5BLASTER]

I disagree. Any adjustable part on your rifle is just going to cause trouble. If your ammo doesn't work with a standard gas block and standard buffer spring and standard buffer then YOU are doing something wrong or outside the norm. Or, maybe, your rifle isn't first rate.

I've shot 100's of highpower rifle matches and I can only say that anything you need to adjust is likely to be wrong. I hate having to adjust my sling but I have a well developed card on what to do. It probably cost me several matches and $100's to get that card right and on a service rifle it would have been much cheaper since there are fewer options. Adjustable stocks are very expensive as there are way too many options: cheek riser height, length, height of butt stock, cant of butt stock...I did just as well with an A2 stock with no adjustments but I couldn't resist so I have an adjustable stock.

I've never had an adjustable trigger. I've seen too many people playing with their triggers when they should have been dry firing. I use CMC two stage triggers that are not adjustable and I'm perfectly happy to not be able to make any adjustments to the trigger although I do make adjustments to my grip and trigger pull when I realize I'm not doing it right while dry firing as I wait for the "targets up" call.

Lol

[grayfox]

I disagree. Any adjustable part on your rifle is just going to cause trouble. If your ammo doesn't work with a standard gas block and standard buffer spring and standard buffer then YOU are doing something wrong or outside the norm. Or, maybe, your rifle isn't first rate.

I've shot 100's of highpower rifle matches and I can only say that anything you need to adjust is likely to be wrong. I hate having to adjust my sling but I have a well developed card on what to do. It probably cost me several matches and $100's to get that card right and on a service rifle it would have been much cheaper since there are fewer options. Adjustable stocks are very expensive as there are way too many options: cheek riser height, length, height of butt stock, cant of butt stock...I did just as well with an A2 stock with no adjustments but I couldn't resist so I have an adjustable stock.

I've never had an adjustable trigger. I've seen too many people playing with their triggers when they should have been dry firing. I use CMC two stage triggers that are not adjustable and I'm perfectly happy to not be able to make any adjustments to the trigger although I do make adjustments to my grip and trigger pull when I realize I'm not doing it right while dry firing as I wait for the "targets up" call.

Well. Guess we should let the experts have it, then. Glad you can shoot thataway. For us mere mortals however, a little adjustment and adaptation is just a normal part of life.

[centerfire]

Were they all out of 30" barrels?