Would you get into 6.5 Grendel in 2024?

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I think 300 whisper (l caught that by the way, and appreciate it, fuck AAC) makes a very effective HD round. Run a short barrel with a can and you can either run subs which is like chucking .45ACP slugs or run supers for better penetration. Either way against unarmored intruders its much easier to shoot accurately than a pistol, with more mag capacity.

My issue is cross contamination. I have so many 556 guns and magazines that I know I would get shit mixed up and blow a barrel. For that reason I have shyed away from it, even though I use 350 legend and 6 ARC/6.5 G. Since neither of those are HD guns, chance of mixing stuff up is much less. Especially under stress.
I use a color/coding system for caliber of weapon, their mags, and the ammo. It works for handguns too.

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I put mine together in 2017. It was always going to be a 20" barrel and setup to reach out there a bit and I always planned to hand load for it. There are so many niche calibers these days (and they all have pros and cons) but when I put it together if you wanted to run a 100+ grain bullet in a small frame AR without going .300 blackout it was the easiest. I'm certainly happy with it but not sure what caliber I'd choose if I did it today.
 
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I just finished building my wife a .223 Wylde, solely because I didn’t already have one, but I wish I had gotten a 6.5 Grendel barrel now. I already have two other 5.56’s and two .300BLK’s, and unless I want to go down the rabbit hole of hand loading my own ammo, a .223 Wylde is a waste.
 
@LRRPF52

I have a friend that would like me to help him assm. a 6.5G, and I am more then willing to help... but, I would like to assist him with a better barrel choice.
His use, would be 95% bench shooting, for accuracy.
He bought a 18" CBC barrel. To my school of thought, that is quite possibly a waste of time and ammo to use that barrel.
And I don't know enough about current moderate priced accuracy minded barrels in 6.5G.

I would like to find something around a Criterion price range, up to 'ish $150+ dollars more.

Gas system length advice would also be appreciated.

Not a heavy profile barrel, since he isn't a large guy... is 18" even really "needed" ?
He also has little shooting skills, but like most of us, he has been bitten by the AR bug.

All suggestions are welcome from everyone.

Thanks ahead of time to all.
What ranges does he have access to and what altitudes are they? Will the other 5% of the time be hunting, recreational, HD, or something else?

My initial gut reaction is 18” ILGS Criterion from PF, bedded into a tight upper that has been squared-up, preferably a billet upper. Use a Rexus Grendel bolt and a quality carrier that can pass the tri-bore armorer’s gauge tests.

For bench shooting, you can go medium-heavy contour like .800”, then step down to .750/.740 to the muzzle. PF makes an ILGS with its own ILGS gas tube. That’s a good length for Grendel in 18” and I wish all my 18” barrels had that gas system length.

The CBC barrel I’m seeing right now with a search is 18” CLGS, which is just really weird and way too much plug dwell time. I can’t say I’ve even heard of them, and I’ve been tracking Grendel barrels on the market now since 2004 when my buddy first got his Grendel.
 
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For barrel lengths shooting 123gr Hornady factory ammo, you’re looking at:

18” 2450-2490fps avg
20” 2490-2530fps
22” 2540-2580fps
24” 2570-2610fps
26” 2600-2640fps
28” ELGS 2630-2670fps

If he has a lighter physique, I would also look at the 100gr ELD-VT. That’s much faster, flies really flat like 6mm, so easy to connect with.

I’ve had really great experiences with the lightweight Lilja Wasp profile 17.6” with .650”, .750”, .740” profile. It’s one of my lightest AR-15s, strings 6 rounds into 8” at 1000yds on rapid. It defies what everyone told me was possible. It’s been consistent like that for 10 years straight. I built it in 2014. The brass deflector is beat to hell past the Cerakote and anodizing, so it has never been a safe queen.

I also have a Lilja 24”, that I have called a 22” all these years, but I guess it’s a 23” really. It’s a bull, heavy fluted pipe that bug-holes. Once you put an AR together with a barrel like that in a billet set with a space telescope 5-25x56, it weighs as much as a heavy AR-10.

One consideration a lot of people overlook is what kind of rifle case you will need. Every long barrel, precision AR or AR-10 I’ve had goes in a Pelican, and those suck to lug around, even the short one that requires the upper and lower to be separated. That’s what I use for my GAP LR-260 and have done so since 2009.

The 17.6” Lilja and 18” LaRue are much easier to throw into a padded soft case with mag pouches on the outside. I haven’t shot the heavy barreled Lilja since 2015 at the latest, and that rifle freaking shoots bug holes. I need to take it out some time, but it’s not my current focus. I usually spent about 3 years with a rifle or carbine getting married to it.

For the past 7 years, my main focus has been on the 12” Grendel. The 17.6” and 18” come along usually, but I really love that 12” for how compact it is, and downrange isn’t much different than a 16” or 18”.
 
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I put this one together last week for a coworker after he shot one of mine. He took a chance on a 16” Aero barrel that was on clearance at B Kings for $88.00. The gun short stroked until we opened the port up, then it ran fine. Hornady Black 123 ELD gave us 1.5” groups. I figured he got what he paid for. We tried some of the 100 gr Vmatch ammo and the little rifle loved it. We cronographed 20 rounds and it averaged 2558 fps. Took it back home and cleaned it and the barrel cleaned up really quick. Barely a trace of copper after shooting 60 rounds through it.

He was certainly happy with the little rifle. Some people seem to get lucky on those bargain barrels.
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I put this one together last week for a coworker after he shot one of mine. He took a chance on a 16” Aero barrel that was on clearance at B Kings for $88.00. The gun short stroked until we opened the port up, then it ran fine. Hornady Black 123 ELD gave us 1.5” groups. I figured he got what he paid for. We tried some of the 100 gr Vmatch ammo and the little rifle loved it. We cronographed 20 rounds and it averaged 2558 fps. Took it back home and cleaned it and the barrel cleaned up really quick. Barely a trace of copper after shooting 60 rounds through it.

He was certainly happy with the little rifle. Some people seem to get lucky on those bargain barrels.View attachment 8486921
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Running a Daniel Defense lower, or just the stock?
 
One consideration a lot of people overlook is what kind of rifle case you will need. Every long barrel, precision AR or AR-10 I’ve had goes in a Pelican, and those suck to lug around, even the short one that requires the upper and lower to be separated. That’s what I use for my GAP LR-260 and have done so since 2009.
You're right. It took me a while to find a 44" case but Voodoo tactical makes one. It's not the best setup but it does offer good protection. The real con is that it doesn't lay flat when fully unzipped. Its far better than lugging a pelican or Boyt though.
 
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What ranges does he have access to and what altitudes are they? Will the other 5% of the time be hunting, recreational, HD, or something else?

My initial gut reaction is 18” ILGS Criterion from PF, bedded into a tight upper that has been squared-up, preferably a billet upper. Use a Rexus Grendel bolt and a quality carrier that can pass the tri-bore armorer’s gauge tests.

For bench shooting, you can go medium-heavy contour like .800”, then step down to .750/.740 to the muzzle. PF makes an ILGS with its own ILGS gas tube. That’s a good length for Grendel in 18” and I wish all my 18” barrels had that gas system length.

The CBC barrel I’m seeing right now with a search is 18” CLGS, which is just really weird and way too much plug dwell time. I can’t say I’ve even heard of them, and I’ve been tracking Grendel barrels on the market now since 2004 when my buddy first got his Grendel.
What do you think of this for an off-the-shelf barrel? Fits your 18 ILGS.
$310.89 shipped right now. Includes adjustable gas block.
 
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What ranges does he have access to and what altitudes are they? Will the other 5% of the time be hunting, recreational, HD, or something else?

My initial gut reaction is 18” ILGS Criterion from PF, bedded into a tight upper that has been squared-up, preferably a billet upper. Use a Rexus Grendel bolt and a quality carrier that can pass the tri-bore armorer’s gauge tests.

For bench shooting, you can go medium-heavy contour like .800”, then step down to .750/.740 to the muzzle. PF makes an ILGS with its own ILGS gas tube. That’s a good length for Grendel in 18” and I wish all my 18” barrels had that gas system length.

The CBC barrel I’m seeing right now with a search is 18” CLGS, which is just really weird and way too much plug dwell time. I can’t say I’ve even heard of them, and I’ve been tracking Grendel barrels on the market now since 2004 when my buddy first got his Grendel.
FWIW, and IMHO, CBC is very low quality. The carbine length gas system also sounds completely wrong. And no one sells match grade barrels that cheaply, Lol. ( FWIW, I haven't mention the dubious barrel choice to him, I wanted to surprise him. )
I would bet the other 5% would be SD.
I was looking at the PF Criterion , but couldn't quite tell if the barrel would be threaded at the end. ( 5/8x24 )

Dooh... the description says 5/8x24

And Thank You for your helpful wisdom.
 
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For barrel lengths shooting 123gr Hornady factory ammo, you’re looking at:

18” 2450-2490fps avg
20” 2490-2530fps
22” 2540-2580fps
24” 2570-2610fps
26” 2600-2640fps
28” ELGS 2630-2670fps

If he has a lighter physique, I would also look at the 100gr ELD-VT. That’s much faster, flies really flat like 6mm, so easy to connect with.

I’ve had really great experiences with the lightweight Lilja Wasp profile 17.6” with .650”, .750”, .740” profile. It’s one of my lightest AR-15s, strings 6 rounds into 8” at 1000yds on rapid. It defies what everyone told me was possible. It’s been consistent like that for 10 years straight. I built it in 2014. The brass deflector is beat to hell past the Cerakote and anodizing, so it has never been a safe queen.

I also have a Lilja 24”, that I have called a 22” all these years, but I guess it’s a 23” really. It’s a bull, heavy fluted pipe that bug-holes. Once you put an AR together with a barrel like that in a billet set with a space telescope 5-25x56, it weighs as much as a heavy AR-10.

One consideration a lot of people overlook is what kind of rifle case you will need. Every long barrel, precision AR or AR-10 I’ve had goes in a Pelican, and those suck to lug around, even the short one that requires the upper and lower to be separated. That’s what I use for my GAP LR-260 and have done so since 2009.

The 17.6” Lilja and 18” LaRue are much easier to throw into a padded soft case with mag pouches on the outside. I haven’t shot the heavy barreled Lilja since 2015 at the latest, and that rifle freaking shoots bug holes. I need to take it out some time, but it’s not my current focus. I usually spent about 3 years with a rifle or carbine getting married to it.

For the past 7 years, my main focus has been on the 12” Grendel. The 17.6” and 18” come along usually, but I really love that 12” for how compact it is, and downrange isn’t much different than a 16” or 18”.
You mentioned billet uppers twice. Respectfully, why ?.
My thought was to use a SOLGW upper., Thermal fit, and the upper has repeatedly had a far better fit on various lowers ranging from much tighter, to "dang" that is a very, very tight fit..., I also always lap the uppers receiver face.

Is there something about billet uppers I have been missing ?
 
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What do you think of this for an off-the-shelf barrel? Fits your 18 ILGS.
$310.89 shipped right now. Includes adjustable gas block.
I have limited first-hand experience with Odin Works, but that profile and weight would fit the bill I was describing.

A buddy of mine brought his 12.5” Odin Grendel to one of my DM Courses and made a 1st-round hit on a ~2 MOA plate at 760yds, shooting Hornady 123gr American Gunner BTHP suppressed. I was pretty impressed.

There was one person that had too large of a feeding cone in their Odin chamber here or on the Grendel forum, but that seems to have been an isolated incident.
 
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You mentioned billet uppers twice. Respectfully, why ?.
My thought was to use a SOLGW upper., Thermal fit, and the upper has repeatedly had a far better fit on various lowers ranging from much tighter, to "dang" that is a very, very tight fit..., I also always lap the uppers receiver face.

Is there something about billet uppers I have been missing ?
More mass for a person with a lighter torso weight. Less limp-torso effect.

The barrel will be the most mass, followed by the optic and BCG.

If you’re having those results with the SOLGW upper, drive on with that.

I usually have about 6 different receiver sets to play with and fit with whatever barrel extension I have just because I’ve been accumulating parts for 4 decades, so my approach is a lot different than it was 20-30 years ago.

We’re spoiled with parts availability nowadays. I like finding receiver sets that fit tight for these types of builds.

Is it more about the face is machined square already vs a forged upper? I grabbed a vltor mur upper for my build, should the face be trued?

Every upper is machined square, but the anodizing can dry unevenly. Manufacturers have gotten better about this over the past 10 years as customers have become more aware of it. When I use the tool, it’s more of a gauge now to ensure the face is square.
 
Imagine a blaster that looks like this:

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......spitting 80gr at over 2600fps. If you go lighter, you can easily exceed 3150fps. We’re entering a new era of High Performance Intermediate Cartridge development, and there has yet to be a case that is as efficient as the 6.5 Grendel with its short propellant column and 30˚ shoulder, with SRP. Crazy thing is that it’s doing this at 48,000-50,000psi, not 55,000 or higher.

My really fast CFE223 loads are only doing 48,000psi because you can’t really put more in the case and get a bullet to seat.
Did you ever do this? Where can I find a 8.5" barrel?
 
Did you ever do this? Where can I find a 8.5" barrel?
Yes. It’s what I’m working on right now. I got my 8.5” barrel from Precision Firearms, a Criterion.

I’m not sure about sleeving it though like that, as everyone with a sleeved suppressor said the handguard gets too hot.

Wait for me to publish my findings about gas system length, projectile weights, performance, and reliability with the system.

I have already had new projectiles made specifically for this project, and the velocities are going to change things.

Imagine having better performance than at least your 14.5”, if not 16” 5.56 guns from an 8.5” barrel.

You already need a 20” 5.56 to match some of the speeds with heavier weights, and none of those can be mag-fed in the 5.56. The 8.5” already has 20” 5.56 mv with an 80gr, and that’s when you load the 80gr .224” to 2.390” COL in 5.56/.223 Rem for single-fed service rifle loads on a led sled. Bye-bye muskets.

Moving forward, I don’t see any barrel lengths longer than 10.5” in my future for a while, other than maybe some 13.9-14.5” to replace any 16-18” pipes I might have already.

Even with legacy 6.5 Grendel cartridges, the 8.5” will spit a 123gr SMK out at 2100fps. That surpasses the 20” SKS 7.62x39 spitting the same bullet weight out at 2350fps mv at 200yds, then adds another 300yds of supersonic speed past the 20” SKS’s supersonic reach.

But I’m more excited by some of these lighter weight bullets. You’re looking at longer barrel 5.56 velocities from an 8.5” PDW, with far less chamber pressure. Terminal effects then favor the larger diameter projectile as well.
 
Yes. It’s what I’m working on right now. I got my 8.5” barrel from Precision Firearms, a Criterion.

I’m not sure about sleeving it though like that, as everyone with a sleeved suppressor said the handguard gets too hot.

Wait for me to publish my findings about gas system length, projectile weights, performance, and reliability with the system.

I have already had new projectiles made specifically for this project, and the velocities are going to change things.

Imagine having better performance than at least your 14.5”, if not 16” 5.56 guns from an 8.5” barrel.

You already need a 20” 5.56 to match some of the speeds with heavier weights, and none of those can be mag-fed in the 5.56. The 8.5” already has 20” 5.56 mv with an 80gr, and that’s when you load the 80gr .224” to 2.390” COL in 5.56/.223 Rem for single-fed service rifle loads on a led sled. Bye-bye muskets.

Moving forward, I don’t see any barrel lengths longer than 10.5” in my future for a while, other than maybe some 13.9-14.5” to replace any 16-18” pipes I might have already.

Even with legacy 6.5 Grendel cartridges, the 8.5” will spit a 123gr SMK out at 2100fps. That surpasses the 20” SKS 7.62x39 spitting the same bullet weight out at 2350fps mv at 200yds, then adds another 300yds of supersonic speed past the 20” SKS’s supersonic reach.

But I’m more excited by some of these lighter weight bullets. You’re looking at longer barrel 5.56 velocities from an 8.5” PDW, with far less chamber pressure. Terminal effects then favor the larger diameter projectile as well.
If you haven't already, it would be awesome if you started a thread on this build. I'd love to follow along.
 
Aero lower with one of the new Magpul moe pr stocks

My new favorite stock. Too much slop but nothing a 2.5" strip of loop side velcro on the buffer tube couldn't fix. They have a DT-PR version that just started shipping, but my DT stock I have is a PITA to adjust so Im holding off on ordering one. With the velcro the PR is awesome.
 
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For those of us that are trapped in states where we can't use SBR's, will the gains in performance be just as good in 16 or 18 inch barrels?
Right now, you can shoot the 80gr Hammer HT at 2950fps from a 16”.

One of the projectiles I had made will do 3440-3539fps from a 16”, so you’re looking at 22-250 performance from an AR-15 carbine without chasing pressure and burning barrels.

From an 18” Grendel, you’d be looking at 3513-3612fps.

If you’re able to do pistols, you can go with the compact form factor for the overall system.

That’s what really excites me right now.

If you can P&W, that also leaves you with some more compactness than a 16” + muzzle device.
 
My new favorite stock. Too much slop but nothing a 2.5" strip of loop side velcro on the buffer tube couldn't fix. They have a DT-PR version that just started shipping, but my DT stock I have is a PITA to adjust so Im holding off on ordering one. With the velcro the PR is awesome.
I wrapped some tape around my A5 RET on the blaster I put it on, the DT-PR. It’s what I’ve been wanting for a carbine stock for a long time.
 
My new favorite stock. Too much slop but nothing a 2.5" strip of loop side velcro on the buffer tube couldn't fix. They have a DT-PR version that just started shipping, but my DT stock I have is a PITA to adjust so Im holding off on ordering one. With the velcro the PR is awesome.
I wrapped some tape around my A5 RET on the blaster I put it on, the DT-PR. It’s what I’ve been wanting for a carbine stock for a long time.

I’m far from being an expert, but have heard the Rogers Super-Stoc to have very tight lockup. Thoughts?
 
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I’m far from being an expert, but have heard the Rogers Super-Stoc to have very tight lockup. Thoughts?
The advantage of the PR stock for me is the built in bag rider. That looks more like the shape of the CTR which is kinda a pain to use with a rear bag. But it looks cool.
 
The Grendel is generally kind of like
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Your cost-to-hit and TGT effects ratio favors the Grendel.

5.56 target ammo ain’t cheap, and hit probability diminishes with wind and distance quite noticeably.

When you do connect, it feels like your manhood shrunk while trying to take a leak into the wind on a freezing day.
 
It’s why I like VLTOR Clubfoot, the DD stock, PRS, and now this for bag-riding and shoulder sleeve grabbing for rear support.

MOE PR just needs a CTR clamping feature, which I bet the roll out after they sell a bazillion of these.
The DT-PR that just dropped has the dual tension feature of the new DT stock. But Im not a fan because it can be hard to adjust and is very noisy for a hunting situation. The PR with about a 1/2"x2" strip of loop side velcro takes the wobble out and is much smoother and quieter to adjust than my DT stock. FWIW
 
The DT-PR that just dropped has the dual tension feature of the new DT stock. But Im not a fan because it can be hard to adjust and is very noisy for a hunting situation. The PR with about a 1/2"x2" strip of loop side velcro takes the wobble out and is much smoother and quieter to adjust than my DT stock. FWIW
Yeah, I removed all the slop with some layers of Scotch tape. It had some of the worst rattle of any new carbine stock I think I’ve ever felt.
 
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Your cost-to-hit and TGT effects ratio favors the Grendel.

5.56 target ammo ain’t cheap, and hit probability diminishes with wind and distance quite noticeably.

When you do connect, it feels like your manhood shrunk while trying to take a leak into the wind on a freezing day.
Don't get me wrong, I believe it is the best value in the AR small frame - have paid the freight as a result
 
It's kind of ridiculous. Makes you wonder if they did it on purpose to sell more of the dual tension models. lol
Could just be parts shrinking in the first mold iteration.

When I got my first PRS stock, it was an earlier generation and in OD Green, before they made adjustments to the manufacturing process. Same with PMAGs, which have gone through numerous mold changes and models.
 
I'd have to say the PMAG, regardless of size/age/generation is the #1 AR related item that I'm just not a fan of. I've had good success with lancers but I've migrated back to metal. For Grendels and 10's I personally think E-Lander for the win
 
I'd have to say the PMAG, regardless of size/age/generation is the #1 AR related item that I'm just not a fan of. I've had good success with lancers but I've migrated back to metal. For Grendels and 10's I personally think E-Lander for the win
I dont know why, but my 18" lilja hates Elanders. I currently have several for sell here. Bullets nose dive enough to break the ballistic tips off of hornady black. Fortunately Duramag is gtg for me.
 
The DT-PR that just dropped has the dual tension feature of the new DT stock. But Im not a fan because it can be hard to adjust and is very noisy for a hunting situation. The PR with about a 1/2"x2" strip of loop side velcro takes the wobble out and is much smoother and quieter to adjust than my DT stock. FWIW
Just so I understand the above:

DT-PR: solid lockup but noisy when adjusting LOP

PR: rattly lockup but fixable with loop velcro or tape. Quieter to adjust LOP.
 
Elanders will gum with dust in the follower, causing it to get stuck in the mag, if you get them away from a clean room environment. I’ve got a pile of them. They’re pretty, but they almost universally suck. I have a couple of 10 rounders that are fine for range day. But, I’ve had too many Elander malfs to trust them if I need them to work.
 
Just so I understand the above:

DT-PR: solid lockup but noisy when adjusting LOP

PR: rattly lockup but fixable with loop velcro or tape. Quieter to adjust LOP.
Well, I cant say for sure the DT-PR will be noisy because I havent handled one yet, but the DT stock i have that uses the same dual tensioning system is pretty bad. Bad enough I might send it to magpul. It is impossible to make a one position adjustment. You have to jerk and torque it to get it to disengage and you end up landing in random positions every time. And it its extremely loud when you do. Its junk if im being honest.
But yes, the PR stock with velcro is butter smooth and nearly silent. There is a little wobble still when fully collapsed, however.
 
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Well, I cant say for sure the DT-PR will be noisy because I havent handled one yet, but the DT stock i have that uses the same dual tensioning system is pretty bad. Bad enough I might send it to magpul. It is impossible to make a one position adjustment. You have to jerk and torque it to get it to disengage and you end up landing in random positions every time. And it its extremely loud when you do. Its junk if im being honest.
But yes, the PR stock with velcro is butter smooth and nearly silent. There is a little wobble still when fully collapsed, however.
Ok, thx for the clarification.

But your DT stock has super solid lockup? I’m not someone that is going to adjust the thing much so I don’t care about noise while adjusting. I’ll change LOP only after changes to hunting clothing thickness.

Also, care to compare the lockup when extended of your DT and PR w/mods? I want it solid as a brick.
 
Ok, thx for the clarification.

But your DT stock has super solid lockup? I’m not someone that is going to adjust the thing much so I don’t care about noise while adjusting. I’ll change LOP only after changes to hunting clothing thickness.

Also, care to compare the lockup when extended of your DT and PR w/mods? I want it solid as a brick.
The DT lockup is comparable to the CTR. Not perfectly solid but close. There is a little more slop in the PR with velcro than the DT they way I have mine setup. I wanted it to be fairly easy to adjust. You can put a wider strip of velcro to take out the remaining slop, but it gets harder to adjust the wider you go. I put too wide of a strip the first try and it was so solid it was very hard to get the stock off. Hope that makes sense.
 
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The UBR Gen 2 is the most solid adjustable stock Ive ever used. Basically zero play and butter smooth adjustment. But its too heavy and no bag rider. If it weighed 6-8oz less and had more of a shelf for a bag it would be the perfect SPR stock.
 
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