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Lilja 6.5 Grendel SBR

corym468

Full Member
Full Member
Minuteman
Oct 5, 2010
602
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Madison, AL
I've got the itch for an 11.5" Grendel Black nitrated barrel. PDW/Truck/Tree Stand Gun. So....

I'm running a group buy over at the Grendel Forum (Grendel Short Barrel Group Buy Orders) and I'm looking to get input on this from the hide. Lilja requires a minimum order of 20 barrels to do this. We're 7 barrels away from the minimum.

NOT LOOKING for a CALIBER DEBATE!

SPECS:
Bolt used for Head Spacing - Maxim Firearms 6.5 Grendel Bolt 0.135" recess*
Fluted - Optional
Contour - 0.725" under the hand guard and in front of the gas block (AR740 Modified)
Gas Block - 0.750" (NO Gas Block Flat)*
Length - 12.5" or 11.5" or 10.5"
Gas System - Carbine Length
Twist - 1-8"
Thread - 5/8X24*
Chamber - 6.5 Grendel per SAAMI Spec reamed with a Manson Reamer*
Optional Coating - H&M Black Nitride (Quote Ferritic Nitrocarburize per AMS2753C) ($5-$10 per barrel + shipping)

* Denotes a Strong Defined Spec

A little draft of what we're looking at.

I estimate weight to come in at
12.5" Fluted - ~21.3oz
11.5" Fluted - ~19.9oz
12.5" - ~22.6oz
11.5" - ~21oz

NFA Disclaimer

Once a sub 16" barrel is assembled into a complete firearm, it becomes a regulated item by the National Firearms Act (NFA), unless assembled into an AR Pistol. Please check with your local and state municipalities for any further regulatory requirements. It is the buyer’s responsibility to make sure they comply with all NFA rules and applicable laws.

Expect no more expensive than $425 per barrel, and fluting $115 per barrel. We're expecting an additional SBR discount.

Black Nitride Service: The barrels will be shipped from Lilja to be black Nitrated then to the buyer.

Thoughts on Length, Contour, Coating, Interest???
 
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I guess I don't see the point in a 11.5" 6.5 Grendel barrel? Black Nitride is the flavor of the week, and I'm not sure how it is worth the added expense I this application? I also don't think that $425 is anything to get excited about.

Not trying to be an ass, but this is a pretty niche barrel.
 
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I know every one has their individual projects, but if I'm buying a Grendel barrel, it's going to be long so I can get out there a little bit- what the Grendel was designed for. Hope your project works out.
 
I guess I don't see the point in a 11.5" 6.5 Grendel barrel? Black Nitride is the flavor of the week, and I'm not sure how it is worth the added expense I this application? I also don't think that $425 is anything to get excited about.

Not trying to be an ass, but this is a pretty niche barrel.

Let's see, home defense, truck gun, tree stand gun, brush gun, medium game hunting within 350 yards.

I've used cerakoted, melonited, and nitrided parts and barrels. All of my barrels will be nitrided from here on out. It's worlds above the other options in durability and its potential to increase the life of the barrel.

Extra expense? It's less than $10 a barrel extra in the GB. That's less than shipping for the barrel. :?

$425 for a top tier barrel is a nice deal. It's a hand lapped match barrel that'll provide accuracy that'll rival any barrel on the market. It isn't a rack grade chrome lined barrel.

Compared to a 5.56 mk13, yea it's a niche barrel. Not compared to any other SBR.

I know every one has their individual projects, but if I'm buying a Grendel barrel, it's going to be long so I can get out there a little bit- what the Grendel was designed for. Hope your project works out.

That's a myth. The Grendel was designed get maximum performance out of the M4/AR15 platform. It was designed as hunting cartridge with potential military applications (DMR, LMG, Carbine), and with competition shooting in mind. The M4/AR15 is IMHO the most versatile rifle on the planet. It's effective from a short 10.3" and shorter to a 24"+ barrel.

An M4 is typically shorter than 16". However when this round was designed the majority of military M4's still had 20" barrels with the number of 14.5"-16" M4s steadily increasing.

During design it was tested and optimized for barrels from 10.5" to 24". The 6.5mm projectile is an inherently long distance capable bullet and the chamber design makes it an exceptionally accurate round. Put that together and it out performs any other cartridge in the AR15 at distance.

By all means I highly suggest an 18" or 20" Grendel to stretch it out to 1000 yards at the range. My first Grendel was a 24" Bull Barrel Lilja build from Precision Firearms. That gun out shoots me all day every day. The build is a work of art. I've since got a 16" Bartlein Barrel from PF, I've built an AR15 around. For me it's the perfect DMR style build. If I had it all to do over again I probably would have started with an 18" Grendel and it probably would have been this (https://secure.wf-api.com/www.preci...-1 6.5 Grendel--arion-6-5-grendel-type-i.html). (When I got my first Grendel I wasn't ready to build my own.) Then my second would have been a 12.5" Grendel.

I love my 24" Grendel (Oden), it excels on the bench and it's a great hunting platform from a static position that I don't have to hump to; however, humping it around is a bitch and maneuvering with it, forget about it.
 
I'll keep this short. I know you didn't want a caliber discussion, but drop the 6.5G and SBR a .300BLK instead. It's made for it, you can get 8.5"bbls. all day long from great manufacturers (including Noveske, who I went with) for less than you are paying now and get better performance at short range with this weapon/caliber.

I love Grendel, I have a 20" that's .33MOA (no shit) and I ordered another Satern bbl. just like it. But for SBR'ing, Form 1's and .300BLK's are your friends.

Basically, the .300BLK is to SBR'ed and suppressed AR's what the 6.5G is to long range, hard hitting AR's. Almost all AR's suppress about the same using supers with an SDN-6 suppressor, but subs from the .300BLK are QUIET. Reportedly quieter than an MP5SD (and it is quieter than some pistol cans I've heard!).
 
The bottom line is there is a reason why you dont see 6.5 SBR barrels more readily available; there are simply other options that are more commonly available (300aac, 6.8) and will get the job done at short range. I have read your posts where you sing the cartridges' praises, but I'm still not convinced that it's worth the added expense over other options to SBR. It's kind of like trying to justify a Ferrari as a daily driver, when the reality is a Kia is better suited for stop and go traffic.
 
I went with 12.5" my self. An honest 2300 ft/s from a 123gr .510 BC pill is nothing to roll your eyes over. When I want quiet I'll put on my 8" 45ACP upper. Super quiet from my TiRant and 230gr common place projectiles that will actually expand at subsonic speeds.
 
I'll keep this short. I know you didn't want a caliber discussion, but drop the 6.5G and SBR a .300BLK instead. It's made for it, you can get 8.5"bbls. all day long from great manufacturers (including Noveske, who I went with) for less than you are paying now and get better performance at short range with this weapon/caliber.

I love Grendel, I have a 20" that's .33MOA (no shit) and I ordered another Satern bbl. just like it. But for SBR'ing, Form 1's and .300BLK's are your friends.

Basically, the .300BLK is to SBR'ed and suppressed AR's what the 6.5G is to long range, hard hitting AR's. Almost all AR's suppress about the same using supers with an SDN-6 suppressor, but subs from the .300BLK are QUIET. Reportedly quieter than an MP5SD (and it is quieter than some pistol cans I've heard!).

I completely agree if shooting subsonic is important to you. I just don't see the point other than the "look guys how quiet my ar15 is, it's almost as quite as your air rifle with a slight advantage in energy."

The bottom line is there is a reason why you dont see 6.5 SBR barrels more readily available; there are simply other options that are more commonly available (300aac, 6.8) and will get the job done at short range. I have read your posts where you sing the cartridges' praises, but I'm still not convinced that it's worth the added expense over other options to SBR. It's kind of like trying to justify a Ferrari as a daily driver, when the reality is a Kia is better suited for stop and go traffic.

If you're the guy that's okay with driving the kia while the Ferrari sits in the garage, that's cool but these aren't the barrels for you. There are cheaper options. However, my daily driver is my LS1 Trans Am. That's how I like it. I don't need the biggest and flashiest, I just need cars and guns that will perform when I need them to, whether that be passing some asshole on the road driving a kia in the fast lane or I've got a trophy buck in my sights and I NEED the bullet to hit where I'm aiming.

I went with 12.5" my self. An honest 2300 ft/s from a 123gr .510 BC pill is nothing to roll your eyes over. When I want quiet I'll put on my 8" 45ACP upper. Super quiet from my TiRant and 230gr common place projectiles that will actually expand at subsonic speeds.

This ^!!!

100gr TTSXs are going be nasty coming from these SBRs.
 
While I wouldn't be interested in an 11.5"or 12.5", I'd dig a 13.5" or 13.75" middy. It'd be interesting to see if it's still holding acceptable velocities at 700-800 yds to put enough energy on small game or lower end of medium game down at that range. Let me know if you're able to tie in one-off custom barrel requests into that group buy. I'd buy a 16" intermediate length gassed pipe as well.

Are you able and/or planning on specifying specific gas port sizes for each length? Or are is Lilja taking care of that?
 
What are you shooting out of a tree stand or out of your truck that you cant kill with a .300aac?

Nobody is disputing that the 6.5 is a badass round, but it's overkill for a tree stand rifle. People are blasting hogs all over the south with the 300aac with no problem; a deer will drop in its tracks when thumped by the same bullet.

Moving beyond the cartridge fanboy discussion (of which I own neither), what does it take to get a 6.5 to run reliably out of a 11.5-12.5" barrel? There isnt a whole lot of info out there on this setup.
 
You really missed my point. I really like the cartridge, and if I wasn't shooting a 6.5 CM, I'd be all over one. But, if I was building an sbr, it's not really on my list. I do, however, wish you good luck with your build.
 
While I wouldn't be interested in an 11.5"or 12.5", I'd dig a 13.5" or 13.75" middy. It'd be interesting to see if it's still holding acceptable velocities at 700-800 yds to put enough energy on small game or lower end of medium game down at that range. Let me know if you're able to tie in one-off custom barrel requests into that group buy. I'd buy a 16" intermediate length gassed pipe as well.

Are you able and/or planning on specifying specific gas port sizes for each length? Or are is Lilja taking care of that?

In the perfect world, yea a 13.5" middy or carbine would be a great rifle. However, I just don't think it's worth dealing with the ATF and their tax stamp. For me if I'm going shorter than a pinned 14.5, it's going to be at least a 12.5" otherwise it's not worth the hassle, IMHO.

Lilja isn't really big on doing one offs. It sounds like you want to experiment and know exactly why you want. If I were you I'd contact Mark at Precision Firearms, The only guy that has more experience building Grendels than him is Bill Alexander. I know Mark has 18" intermediates and has probably experimented with what you've asked for. Hit him up, he'll build you exactly what you want with quality that few shops will even rival.

We're going with a 0.078" port per the suggestion of Bill A.

What are you shooting out of a tree stand or out of your truck that you cant kill with a .300aac?

Nobody is disputing that the 6.5 is a badass round, but it's overkill for a tree stand rifle. People are blasting hogs all over the south with the 300aac with no problem; a deer will drop in its tracks when thumped by the same bullet.

Moving beyond the cartridge fanboy discussion (of which I own neither), what does it take to get a 6.5 to run reliably out of a 11.5-12.5" barrel? There isnt a whole lot of info out there on this setup.

If you want to go that route, what can the Black Out do that my 5.56 can't other than be weally weally quite.

AA had been selling 10.5" Grendels that ran perfectly reliably with a fixed gas block. You need a carbine gas system, mil spec full auto bcg, and a heavy buffer (I'm running a spikes T2). I'm going to throw an adjustable gas block on her(Fenrir), because I plan to run her suppressed.

You really missed my point. I really like the cartridge, and if I wasn't shooting a 6.5 CM, I'd be all over one. But, if I was building an sbr, it's not really on my list. I do, however, wish you good luck with your build.

Huh if you're pet rifle is a 6.5 CM then I'd think you'd chose an SBR in 6.5mm for one of the biggest reasons I'm going with a Grendel in an SBR. My main AR15 is a 16" Grendel. I've got a 5.56, but I see no benefit in shooting dozens of different cartridges. This SBR will share brass, bullets, primers, powder, and factor ammo with my main AR15. This will save me money and allow me to become more efficient with these rifles at a more rapid pace. Assuming a 6.5 Grendel SBR meets your requirements of an SBR, I'd think the fact that you can share the 123gr projectiles between rifles, allowing you to buy them in bulk and stock up on them, would at least lead you to take a serious look at the Grendel.
 
No way I'd cut the balls off a .264 that much. If you want a azz kicker of a SBR, go with a 6.8. ARP is out of their 12.5" but Wilson Combat has some 11.3" and MDWS could get you even shorter.

If Lilja could use ARP's specs, that would be a nice 6.8 barrel.

While hunting season is coming up, I'd hate to get stuck with a bunch of short .264 barrels that won't sell..
 

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Sounds like an interesting project. Your parts list mentions "no gas block flat". I'm not sure what this means, could you explain? Good luck and keep us posted.
 
If you want to go that route, what can the Black Out do that my 5.56 can't other than be weally weally quite.

AA had been selling 10.5" Grendels that ran perfectly reliably with a fixed gas block. You need a carbine gas system, mil spec full auto bcg, and a heavy buffer (I'm running a spikes T2). I'm going to throw an adjustable gas block on her(Fenrir), because I plan to run hssed.

300AAC:

-standard, cheap, relaible mags found anywhere
-standard bolt
-readily available match grade barrels
-more readily available ammo options
-unlimited cheap brass
-runs standard ammo and suppressed subs with no gas block adjustments
-low velocity

6.5:
-expensive mags
-tricky getting subsonic
-expensive brass that I dont think can be formed from any other case (could be wrong here)
-Expensive bolts that some will argue are more sensitive
-high velocity
-high BC bullets

What is it about the 6.5 that screams SBR? Nothing. It shines as long range cartridge with better trajectory and windage than the other AR15 calibers. In an SBR, most of us don't care about, or need the extra velocity of the 6.5. What most people look for in an SBR is reliability and ability to be supressed........which is what the 300aac does best. Most of us arent looking to shoot groups with our SBR; that's why we have long range rifles such as a 16"+ 6.5 or 6mmAR, or even .223.
 
No way I'd cut the balls off a .264 that much. If you want a azz kicker of a SBR, go with a 6.8. ARP is out of their 12.5" but Wilson Combat has some 11.3" and MDWS could get you even shorter.

If Lilja could use ARP's specs, that would be a nice 6.8 barrel.

While hunting season is coming up, I'd hate to get stuck with a bunch of short .264 barrels that won't sell..

300AAC:

-standard, cheap, relaible mags found anywhere
-standard bolt
-readily available match grade barrels
-more readily available ammo options
-unlimited cheap brass
-runs standard ammo and suppressed subs with no gas block adjustments
-low velocity

6.5:
-expensive mags
-tricky getting subsonic
-expensive brass that I dont think can be formed from any other case (could be wrong here)
-Expensive bolts that some will argue are more sensitive
-high velocity
-high BC bullets

What is it about the 6.5 that screams SBR? Nothing. It shines as long range cartridge with better trajectory and windage than the other AR15 calibers. In an SBR, most of us don't care about, or need the extra velocity of the 6.5. What most people look for in an SBR is reliability and ability to be supressed........which is what the 300aac does best. Most of us arent looking to shoot groups with our SBR; that's why we have long range rifles such as a 16"+ 6.5 or 6mmAR, or even .223.

What part of I'm not looking for a caliber debate do y'all not understand?

The fact is a Deer will never know the difference in a 6.8 SPC and Grendel at relatively short range.

Sounds like an interesting project. Your parts list mentions "no gas block flat". I'm not sure what this means, could you explain? Good luck and keep us posted.

If you look on Lilja's website and the drawings of their ARs, they machine a flat out of the bottom of the gas block journal. It's for gas blocks with set screws. During the original group buy the majority of the guys opted not to have it. So I'm being retroactive in this group buy.
 
We're just giving our input.

Good luck man.

Alright Fine.

...What is it about the 6.5 that screams SBR? Nothing. It shines as long range cartridge with better trajectory and windage than the other AR15 calibers. In an SBR, most of us don't care about, or need the extra velocity of the 6.5. What most people look for in an SBR is reliability and ability to be supressed........which is what the 300aac does best. Most of us arent looking to shoot groups with our SBR; that's why we have long range rifles such as a 16"+ 6.5 or 6mmAR, or even .223.

No what most people look for in a rifle is lethality and effectiveness. What most people look for in an SBR is to retain as much lethality and effectiveness in the lightest smallest package that's extremely easy to maneuver in tight spaces and easy to carry.
 
While I wouldn't be interested in an 11.5"or 12.5", I'd dig a 13.5" or 13.75" middy. It'd be interesting to see if it's still holding acceptable velocities at 700-800 yds to put enough energy on small game or lower end of medium game down at that range. Let me know if you're able to tie in one-off custom barrel requests into that group buy. I'd buy a 16" intermediate length gassed pipe as well.

Are you able and/or planning on specifying specific gas port sizes for each length? Or are is Lilja taking care of that?

I have a 14.5" upper with a chrome lined Saber defence barrel I'm looking to sell. Factory Hornady 123 @ 2460 ft/s According to my magneto speed.
 
What are you shooting out of a tree stand or out of your truck that you cant kill with a .300aac?

Nobody is disputing that the 6.5 is a badass round, but it's overkill for a tree stand rifle. People are blasting hogs all over the south with the 300aac with no problem; a deer will drop in its tracks when thumped by the same bullet.

Moving beyond the cartridge fanboy discussion (of which I own neither), what does it take to get a 6.5 to run reliably out of a 11.5-12.5" barrel? There isnt a whole lot of info out there on this setup.

I just cut a 18" midlegnth barrel down to 12.5". Runs just fine with no tinkering at all.
 
Curious to know how it works out. I kind of want to SBR mine. It started as an 18" "DMR" and has slowly shrunk and become a carbine.

Not interested in the least at subsonic 160-220gr bullets. If I was, I'd suppress my 1911. If I want quiet, I'll do it with a bolt gun. However, 123gr 6.5's at 2300 fps is a pretty lethal 300-and-in rig that can probably be pretty damn light/small/handy.
 
Well here goes
grendel is still supersonic at 1000y with 123gr out of a 14.5" barrel. Show me another ar15 platform round that can do that. So how can you say it wasnt intended for an sbr round? I ring steel with my 10.5" at 500y no problem. Carbine gas works just fine with it no issues. This is a great idea. If i wasnt already set with mine id get in.
 
In the perfect world, yea a 13.5" middy or carbine would be a great rifle. However, I just don't think it's worth dealing with the ATF and their tax stamp. For me if I'm going shorter than a pinned 14.5, it's going to be at least a 12.5" otherwise it's not worth the hassle, IMHO.

Lilja isn't really big on doing one offs. It sounds like you want to experiment and know exactly why you want. If I were you I'd contact Mark at Precision Firearms, The only guy that has more experience building Grendels than him is Bill Alexander. I know Mark has 18" intermediates and has probably experimented with what you've asked for. Hit him up, he'll build you exactly what you want with quality that few shops will even rival.

We're going with a 0.078" port per the suggestion of Bill A.

I was just trying to see if there was a way I could help you out brother. Chasing yet another 6.5 project definitely wasn't something I was planning on.....unless I had an excuse of course and it'd help you get to that barrel total. I'm pretty happy with my 18" JP for now. Next time though.

Either way, keep us updated on the project. I really am curious to see how that works out. I've had a perfect ideas on paper a bunch of times too. Some worked out pretty close to what I expected, others not so much. Don't mean to insinuate that's what will happen with this one, I'm just wore the fuck out with the custom stuff at the moment. Maybe when you report back with the results I'll be motivated to take one up. Good luck my man!
 
Thanks man! We'll hit the minimum barrel mark, we only need 6 more barrels ordered.

I'm confident these barrels will work reliably. A lot of guys are going to wish they had jumped on this after we start posting results.
 
I just ordered a 7.5 inch grendel barrel or I would be on board. I'm building it for the same reasons as you and am going the pistol route. Can't wait to start playn with it and see what it will do. Your thread choice is smart much more options that way. Best of luck!
 
Black Hole has offered them in 7.5, 9.5, 10.5 & 11.5 for a while now. "A while" meaning a few months. A 7.5" should be interesting fo' sho'
 
Ya I ordered it from there the price is certainly right since I definetry feel like I am experimenting with a grendel barrel that short, but Ivery heard good things about them so I'm pumped to see what happens. I got everything but the barrel and bolt for the build, I'll post about it once it's built and see what it can do on paper and deer/hogs
 
corym468,

I applaud what you are doing here. While many feel the 6.5 Grendel is limited to long range as an "efficient" bullet/cartridge combo, it also makes it a great short range round. It may not be the most efficient in this realm (short range). But, it certainly fills the bill without question. I can't see where it's overkill from a tree stand when people use 30-06's (and bigger) all the time.

As far as what you are describing here, I see a world of component interchangeability here. Provided the two chambers match. You can have one long range upper/bolt gun and the SBR here to do the close in work.

As mentioned, no cartridge comparisons/debates. So, the only drawback I see here is the 20% capacity over the 5.56/.223 This has been addressed with the .078" gas port. A much better option IMO than the .093"-.096" port originally prescribed by Bill Alexander. Of course his was rifle length yours will be less than carbine length. But, if it operates it will have plenty of power. Operating correctly will give it plenty of reliability.

In this case, you reloaders out there, stay away from AA2520 for this. Not the same as what AA uses for their rifle length tubes.
 
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I'd be all over it if I was in the US. a Grendel is still the best thing you can jam into an AR15, even down to a 10.5"


.300aac is overrated + over marketed, who gives a shit about subsonic etc etc
 
I'd be all over it if I was in the US. a Grendel is still the best thing you can jam into an AR15, even down to a 10.5"


.300aac is overrated + over marketed, who gives a shit about subsonic etc etc

Bevan,

I like your first statement. I don't agree (in whole) with your second. The .300 AAC is highly marketed because Big Green wants to sell it now. It was growing pretty rapidly by word of mouth when it was the .300 Whisper. The point in going to the .300 AAC (from the whisper) was to circumvent the U.S. patent system. JD Jones wanted more for it than it was worth to build an entirely new system. So they made enough changes and built the new system.

FWIW, Subsonic is flat out awesome when you want to shoot quietly. The Energy given while subsonic can be devastating out to 200 yds. But, as noted anything that goes subsonic at the muzzle doesn't go supersonic all that well. This is where the .300 AAC gets left in the dust. But, AAC fans will never admit to it. And, like you, I'm tired of that.