Upgrade a cheap 6.5 Grendel for 1 MOA?

zach__

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Aug 6, 2022
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I'm new to the AR-15 platform and would like to build a sub 1 MOA 16'' 6.5 grendel as cheaply as possible for deer/hog hunting <300 yards. Radical firearms are very cheap ($450). If I throw on a ballistic advantage barrel ($205) and a LaRue Tactical MBT-2S Trigger ($99) and maybe an adjustable gas block, could I expect 1 MOA and reasonable reliability? It feels wasteful to throw out the barrel but looks cheaper than buying the individual parts. Any other ideas?

Thanks,
Zach
 
I think the barrel is the big thing. Drop most of your budget there. I’ve had great success with Odin Works and Wilson Combat barrels. Others here will suggest other manufacturers as well.

The Larue MBT is a good choice, too. Almost as nice as the Geissele options at a fraction of the cost.

Will this be suppressed? If not, I don’t know that you really need to use an adjustable gas block.
 
The ballistic advantage barrel advertises a sub moa guarantee, so that's what I'm banking on. I googled about the bolt. It looks like the radical firearms uses a .136 bolt, so would that be good to go? https://av8rtactical.com/product/6-5-grendel-type-ii-bolt-carrier-group/
The type of bolt needed depends on the barrel maker and their chamber of choice. BA uses the "Type II" .136 bolt for their Grendel offerings.
I assumed you are trying to convert a less expensive .223 rifle to 6.5 Grendel.
 
The type of bolt needed depends on the barrel maker and their chamber of choice. BA uses the "Type II" .136 bolt for their Grendel offerings.
The type of bolt needed depends on the barrel maker and their chamber of choice. BA uses the "Type II" .136 bolt for their Grendel offerings.
I assumed you are trying to convert a less expensive .223 rifle to 6.5 Grendel.

I assumed you are trying to convert a less expensive .223 rifle to 6.5 Grendel.
Ya, the radical firearms is in 6.5 grendel, but converting a .223 rifle might be an even better idea. I could keep the .223 barrel for cheap plinking.
 
If starting with a 6.5 Grendel as is, see what it does out of the box.
If going to drop the coin for a new barrel with the express goal of accuracy save and expand your budget to get a better quality barrel.

Maybe you get lucky and the Radical works well or can be tuned enough via reloading, the same goes for the "sidegrade" the BA is.

The chances of something like the Craddock shooting well with anything you use is much higher, short of the odd diameter Wolf steel crap ammo.
 
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IMHO, while BA says they can shoot.. their guarantee, is with 3 rd groups. Frankly you might get lucky, you might not.

Given the cost of ammo, I would tend to spend more money on a better barrel. You could readily use $100 bucks worth of ammo trying to make your BA barrel shoot to your expectations.

I understand your budget aspect, but spending more for a barrel will pay off in the long run. Wilson has a 18" in stock right now.
 
I had a BA barrel that wouldn't shoot, but they replaced it under warranty pretty quickly and the replacement was a lot better.

I made a hog rifle with a WC 6.5 Grendel barrel and BCG. It will shoot sub minute groups fairly routinely.

I also like the LaRue MBT2S.
 
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Generally speaking, I would not consider a BA barrel as an upgrade.

If you’re going really cheap, shoot the gun before dropping any more money in parts.

But, in the long run, I feel that you are money ahead by building what you want the first time.
 
IMHO, while BA says they can shoot.. their guarantee, is with 3 rd groups. Frankly you might get lucky, you might not.

Given the cost of ammo, I would tend to spend more money on a better barrel. You could readily use $100 bucks worth of ammo trying to make your BA barrel shoot to your expectations.

I understand your budget aspect, but spending more for a barrel will pay off in the long run. Wilson has a 18" in stock right now.
That's true, but Wilson is only $40 more than BA and their guarantee is "get lost." I do understand the appeal of a better barrel though and will keep researching them. My plan now is to grab the Radical Arms 16'' 6.5 grendel and replace the trigger. I'll replace the barrel if I'm getting worse than let's say 1.25 MOA.


Wilson Combat AR Barrel Service Policy


Because of the nature of the AR parts business and varying pressures of commerically availle ammunition, Wilson Combat cannot guarantee function in customer built AR rifles. We recommend all components be installed by a competent rifle-smith.


If you assemble a firearm with Wilson Combat components and it fails to function, you first need to check the fit of the barrel to the gas block and the overall condition of your rifle's gas system/bolt carrier group to ensure your system isn't leaking gas. As buffers and springs play a role in overall reliability, the use of an aftermarket style buffer system is not recommended. When using an adjustable gas block, reliability is best achieved at the fully open setting without any gas port restriction.


Wilson Combat will not troubleshoot customer built firearms/uppers.


If you feel a Wilson Combat component is defective, please return the component only to us using our Return Form. Shipping to Wilson Combat is the responsibility of the consumer.
 
I'm new to the AR-15 platform and would like to build a sub 1 MOA 16'' 6.5 grendel as cheaply as possible for deer/hog hunting <300 yards. Radical firearms are very cheap ($450). If I throw on a ballistic advantage barrel ($205) and a LaRue Tactical MBT-2S Trigger ($99) and maybe an adjustable gas block, could I expect 1 MOA and reasonable reliability? It feels wasteful to throw out the barrel but looks cheaper than buying the individual parts. Any other ideas?

Thanks,
Zach
I would take it step by step.
Replace your trigger first, the MBT 2 is a great trigger. That, itself, will likely yield better accuracy.
 
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If you're looking for an affordable Grendel barrel, is hard to beat SixFive Outfitters. They are made from Green Mountain blanks, which are known for making great barrels for the money. There is no "guarantee" but they are well known in the SixFiveGrendel forum community as being consistent shooters with factory hunting ammo. I'm planning on buying a 12" for my next build (eventually).

 
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Another source of 6.5 Grendel barrels:


The Rainier stuff in .223 / 5.56 has a pretty good reputation for accuracy. I have a Liberty 18" barrel and a Compass Lake 20" barrel on a Bartlien 5R blank that I haven't started working with yet.
 
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I just did the same build. However I took a low end PSA 556 pistol I had laying around. Added a CMC trigger that is a spare and then ordered the PSA 12” upper with bcg
And adjustable gas block. The upper is $350 delivered. Swapped uppers added my old Gemtech HVT and it shoots right at 1 MOA at 100. This is with a Pulsar thermal XQ50 that is 3 generations old. Yeah I have a lot of old stuff laying around and I am constantly upgrading and creating a “spares” parts bin. I’ve had the thermal on 4 different host and this one is the easiest to hunt with. The pistol brace is slightly challenging but for Minute of Hog at night I limit my shots to 200 yards or what I perceive is that distance through the thermal. So far runs great and seems to work.
 

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I would put the funds into the barrel. That will give you the precision. There is a lot of good info suggestion on barrels posted by others. I have a Satern on my Grendel that I have had for years. It hovers sub MOA consistently. I would say look into Rainier Ultramatch barrels. I have one on one of my Creedmoors and it is fantastic. I would not hesitate to purchase another and will when I look for a 6mm ARC barrel soon.

The trigger, will help you more than the rifle. MBT is a good mid range trigger and doesnt compare to Geissele, AR Gold, TriggerTech, Elftman, etc... I have had 4 and am down to one that was put into an AR10 lower as a mockup. Clunky and chunky trigger. I have an AR Gold in the Grendel mentioned above. Only thing I would change it out for is a HSNM.

Adjustable gas may help with your shorter req's. Mine is 20" and I have never run an adjustable on it. On both my Creedmoor's I have SLR adjustable gas blocks. They work really well, but there are others that I am sure are good too. I have never seen or had a reason to change the regular gas block the Grendel currently has to an adjustable.
 
Later on if you decide on a suppressor, then change the gas block to an adjustable, for non suppressed / supersonic the standard gas block will be fine.
The MBT in a very good trigger, and you have to spend quite a bit more more money for marginal improvement.

Spending a little more money on a better barrel improves the odds that you'll get a barrel that isn't as finicky as to what you feed it and will shoot better in the long run. That $ 100.00 in cost between two barrels will go quickly with 4 boxes of Hornady Black ammo or a couple of boxes of bullets, a pound of powder and a couple of boxes of primers if you get a lemon barrel that wont shoot.
 
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I'd scratch the BA barrel. Had a couple. None were sub moa then you have to send it in and they'll most likely tell you that it's you and not the barrel. I don't know what your exact budget is, but Look into criterion. I believe there shortest offering in 6.5g is 18 inches though. Rainer arms as well, perhaps Wilson. I researched for months before buying my 6.5 g barrel. Have no first hand experience, but have read many great things about Saturn barrels as well. Maybe even look into Alexander arms barrels. They made the round so maybe they know a thing or two about those barrels.