• Watch Out for Scammers!

    We've now added a color code for all accounts. Orange accounts are new members, Blue are full members, and Green are Supporters. If you get a message about a sale from an orange account, make sure you pay attention before sending any money!

New - LaRue 6.5 Grendel Rifle

MSTN

Sergeant
Full Member
Minuteman
Jan 31, 2010
1,236
2,369
MIDDLE OF ARIZONA
mstn.biz
Mine just arrived. Thought you might like to see it. I'm extremely pleased with the fit and finish.

This rifle gives you the long range performance of a big block gas gun at a small block gas gun weight - and price.
[IMG2=JSON]{"data-align":"none","data-size":"full","src":"http:\/\/photos.imageevent.com\/mstn\/laruecostaedition556\/huge\/IMG_6563.jpg"}[/IMG2]
[IMG2=JSON]{"data-align":"none","data-size":"full","src":"http:\/\/photos.imageevent.com\/mstn\/laruecostaedition556\/huge\/IMG_6564_1.JPG"}[/IMG2]
[IMG2=JSON]{"data-align":"none","data-size":"full","src":"http:\/\/photos.imageevent.com\/mstn\/laruecostaedition556\/huge\/IMG_6565.JPG"}[/IMG2]
[IMG2=JSON]{"data-align":"none","data-size":"full","src":"http:\/\/photos.imageevent.com\/mstn\/laruecostaedition556\/huge\/IMG_6566.JPG"}[/IMG2]
[IMG2=JSON]{"data-align":"none","data-size":"full","src":"http:\/\/photos.imageevent.com\/mstn\/laruecostaedition556\/huge\/IMG_6567.jpg"}[/IMG2]


[IMG2=JSON]{"data-align":"none","data-size":"full","src":"http:\/\/photos.imageevent.com\/mstn\/laruecostaedition556\/huge\/IMG_6569.jpg"}[/IMG2]
 
Last edited:
Sweet. Wes, is this the complete 6.5 FDE package, or the more recent upper (only) sale that Mark is doing? I signed up for the latter, and will get my Grendel in a week or so, but have to mate it with an existing lower. It will be my first 6.5.
 
Sweet. Wes, is this the complete 6.5 FDE package, or the more recent upper (only) sale that Mark is doing? I signed up for the latter, and will get my Grendel in a week or so, but have to mate it with an existing lower. It will be my first 6.5.

I did the same as you. Called and talked to LT, and found out that the Builder's kit is exactly the same, part for part, with the exception of just not having the lower. So I ordered my 6.5G kit in Black because they won't tell you exactly what type of FDE they use so you can't get a perfect match with your lower.

The same day I placed the order for the Grendel Builders kit I ordered a lower from Rainier Arms for $200.00 Shipped and the Builder's kit was 799.99, so basically you and I have the same rifle as above, same accuracy Guarantee for $1000.00 less. I'm even flirting with the idea of picking up as SR15 Lower and dropping in a 20" Grendel Proof CF Barrel.
 
Mine just arrived. Thought you might like to see it. I'm extremely pleased with the fit and finish.

This rifle gives you the long range performance of a big block gas gun at a small block gas gun weight - price.

[IMG2=JSON]{"data-align":"none","data-size":"full","src":"http:\/\/photos.imageevent.com\/mstn\/laruecostaedition556\/huge\/IMG_6563.jpg"}[/IMG2]

[IMG2=JSON]{"data-align":"none","data-size":"full","src":"http:\/\/photos.imageevent.com\/mstn\/laruecostaedition556\/huge\/IMG_6564_1.JPG"}[/IMG2]

[IMG2=JSON]{"data-align":"none","data-size":"full","src":"http:\/\/photos.imageevent.com\/mstn\/laruecostaedition556\/huge\/IMG_6565.JPG"}[/IMG2]

[IMG2=JSON]{"data-align":"none","data-size":"full","src":"http:\/\/photos.imageevent.com\/mstn\/laruecostaedition556\/huge\/IMG_6566.JPG"}[/IMG2]

[IMG2=JSON]{"data-align":"none","data-size":"full","src":"http:\/\/photos.imageevent.com\/mstn\/laruecostaedition556\/huge\/IMG_6567.jpg"}[/IMG2]

IMG_6569.jpg

MSTN, do you know the weight of your Grendel without Optics?
 
Sweet. Wes, is this the complete 6.5 FDE package, or the more recent upper (only) sale that Mark is doing? I signed up for the latter, and will get my Grendel in a week or so, but have to mate it with an existing lower. It will be my first 6.5.

Mine is the complete rifle.

The value you get for the $$$ in the LaRue Builder's Kit is absolutely insane.
 
I did the same as you. Called and talked to LT, and found out that the Builder's kit is exactly the same, part for part, with the exception of just not having the lower. So I ordered my 6.5G kit in Black because they won't tell you exactly what type of FDE they use so you can't get a perfect match with your lower.

Totally agree. I have the 7.62 t'OBR FDE, and the color is not Magpul Cerekote FDE. I wish I was smart enough to be able to match the color, or have Mark tell us.

The same day I placed the order for the Grendel Builders kit I ordered a lower from Rainier Arms for $200.00...

Yeah, but what lower is that, and how well does it look and fit a LaRue ? I broke down and bought a LaRue lower, but for the price, I could have purchase an entire Colt M4. I am looking for an older SMOS SM-15, which is the LaRue pattern. I found some, but they all have the mule on the right magwell. The early SMOS lowers had no logo, and only minor ATF required on the left side.

 
Just got mine all set up!
b10ecba86e4e342d6bc2e809dc3a579c.jpg

Very nice. Now, you have the FDE LT104, it looks like. Did you buy that as a follow-up, or get the Burris package? I thought it was not such a good Burris Mark was offering. Nice to have the matching mount. It would be like have a Prada bag and Coach shoes if you didn't. :eek::eek:

 
Totally agree. I have the 7.62 t'OBR FDE, and the color is not Magpul Cerekote FDE. I wish I was smart enough to be able to match the color, or have Mark tell us.



Yeah, but what lower is that, and how well does it look and fit a LaRue ? I broke down and bought a LaRue lower, but for the price, I could have purchase an entire Colt M4. I am looking for an older SMOS SM-15, which is the LaRue pattern. I found some, but they all have the mule on the right magwell. The early SMOS lowers had no logo, and only minor ATF required on the left side.

I'll post pics when it arrives on the 8th..
 
Magpul FDE is Cerakote color code #H-267.

Just plain old "FDE", Cerakote color code H-265, is what I'd wager LaRue is using. H-265 matches Magpul and LaRue plastic parts better than the Magpul H-267 does.

The LT104 mount in FDE looks extra sharp on your rifle.
 
Very nice. Now, you have the FDE LT104, it looks like. Did you buy that as a follow-up, or get the Burris package? I thought it was not such a good Burris Mark was offering. Nice to have the matching mount. It would be like have a Prada bag and Coach shoes if you didn't. :eek::eek:

I bought the rifle only. The FDE 104 was included with the rifle purchase. Not just if you bought the Burris glass.


Sent from my iPhone using Tapatalk
 
I get a fair amount of custom Cerakote done through various sources. I've yet to see anything done any better than this rifle.

The trigger is a VERY sweet and consistent 3.5 LB, too.
 
Took two weeks. ELD match from Hornady shoots very nice. Ordered a couple boxes from Copper Creek of 130 Berger VLD. Hopefully no feeding issues.
 
Just got mine in yesterday, if anyone wants the stock, muzzle brake buffer and spring.. I'll sell them as a package deal for $170.00 shipped
all parts are in BLK
 
Last edited:
I've got an upper on order. Assemble it yourself and you save another $200. Grand total for everything was $800. Best deal I've ever even heard about for a Larue. Selling a few of the extra parts I don't need will make it even cheaper.

I can't wait to slap it on my Mega lower and see what it does!


Sent from my iPhone using Tapatalk
 
I get a fair amount of custom Cerakote done through various sources. I've yet to see anything done any better than this rifle.

The trigger is a VERY sweet and consistent 3.5 LB, too.

MSTN..
What types of ammo have you used in you're Grendel and what has worked best.??
 
When purchasing the upper kit, do you have to buy the brake or is the site not loading right for me?
 
See above pic... .392" his first time out.

I shot a .07" 3 shot "group" with one of Gaps when I was doing sight in. Guess it's a 1/10" rifle.

3 shot groups don't count and from what I read these are .75-1.25" rifles and some have reliability issues. I was looking at the rifle deal minus the lower.
 
I've completed my LT 6.5 Grendel Builders kit and this is my opinion since completion.

The barrel and other components seem to be quality, but I am disappointed and how the upper receiver is machined. On the left hand side of the upper receiver towards the rear you can see how thin the wall of the receiver is and due to this, it does not fit properly with any lower receiver that I own and that list consists of Aero Precision, Les Baer, Seekins Precision, ATX Armory and KAC. The wall on the left side of the receiver is so thin it leave a 0.020 gap from the side.

The Muzzle brake looks good, but it wasn't well thought out because you have no protection for the outside threads for the suppressor.
IMG_20170810_152715269.jpg
IMG_20170810_152756048.jpg
IMG_20170810_154111995.jpg
 
  • Like
Reactions: Pseudohero
MSTN..
What types of ammo have you used in you're Grendel and what has worked best.??

I'm still pretty busted up at the moment from an accident back in May. No actual trigger time for me yet. I have at least had the time to program all of my ballistics into both Field Firing Solutions and Applied Ballistics.

I do have a 6.5 G that I built this past Spring that seems to show a slight preference for the Hornady 123 AMAX over the Hornady 120 ELD. But, I think every gun - and every lot of ammo - has the potential to be a little different.

 
I'm still pretty busted up at the moment from an accident back in May. No actual trigger time for me yet. I have at least had the time to program all of my ballistics into both Field Firing Solutions and Applied Ballistics.

I do have a 6.5 G that I built this past Spring that seems to show a slight preference for the Hornady 123 AMAX over the Hornady 120 ELD. But, I think every gun - and every lot of ammo - has the potential to be a little different.

Looks like yours has that same gap that mine does could you take some pics at the angles I did in my post above?
 
I've completed my LT 6.5 Grendel Builders kit and this is my opinion since completion.

The barrel and other components seem to be quality, but I am disappointed and how the upper receiver is machined. On the left hand side of the upper receiver towards the rear you can see how thin the wall of the receiver is and due to this, it does not fit properly with any lower receiver that I own and that list consists of Aero Precision, Les Baer, Seekins Precision, ATX Armory and KAC. The wall on the left side of the receiver is so thin it leave a 0.020 gap from the side.


This is a bit concerning to me, has anyone else seen this problem yet?

 
So I just went on to LaRue Tactical website to see if they publish my 3 star review of his new Grendel Builders kit, and to no surprise it's not published.. But take a look at this Beauty that was posted in the review section. If any of you have ever read Mark Larue write-ups you know this reads suspiciously similar to his writing style and detail.

Reviewed by LRRPF52 4 days ago
Wow. What a superb piece of craftsmanship and mechanical engineering. As I pulled this rifle from the plastic inside the hard case it was shipped in, I notice the exceptional fit, feel, and finish of the components. Right off the bat, you visually appreciate how the FDE furniture and Cerakote all match perfectly. As you hold the rifle, there is no play in the receivers, stock-to-extension tube fit, and handguard-to-upper. It has a solid overall feel testament to the billet construction and extreme pursuit of precision fitting of all the parts, not just some of the pars like with many other rifles. Retracting the charge handle and BCG to the rear feels like glass riding on oil, as if the rifle was tuned and polished for optimal coefficient of friction in the cycling parts from the factory. The FDE RAT stock slides smoothly on the extension tube, without the typical rattle I commonly see on other AR15s. It has the nice touch of including laser-etched numerical position indicators on the comb of the tube. The elastomer buttplate has very positive purchase to your shoulder without any indication of slipping. In the sea of various after-market stocks for the AR15, I immediately regret overlooking this one. The rifle includes the MBT-2S superb 2-stage trigger with amazingly crisp and short 2nd stage. No need to mess with fire control on this rifle, as it has a world-class trigger in it designed, tested, and built in-house by LaRue. Looking over the lower receiver, I notice that there is a recess cut into the pivot pin detent spring channel boss for the ejection port door plunger assembly plate. Normally, this plate will impact your finish and begin to mar it over time. Not so on the LaRue rifle. So many little details like this have been accounted for and intelligently solved with CNC precision. Upon actuation of the ejection port door, the inside is etched with "LaRue", a nice touch. The entire port door assembly is also Cerakoted in Flat Dark Earth, unlike most other rifles that include Cerakote. Port doors are one of the first steel components on the AR15 to experience corrosion in a high humidity environment in my experience, so it's a testament to a shop that likes to go above and beyond when applying their finishes to small parts that would normally be overlooked. As you push out the takedown pin and shotgun the receivers, it's like cracking open a vault door at NORAD. Instead of giving a little and then slamming open, it doesn't move, then slowly begins to just barely break the seal, then smoothly pivots like it's on oiled ball bearings. There is no left-to-right play, let alone seam-play like on most other AR15 receiver sets. Someone went through extra trouble getting these receivers to fit this tightly. Looking at the barrel extension, the ramps appear to be polished to me, which is something I normally do on my custom builds, but never really see on factory guns. Inspecting the bolt, I see that the extractor face ramp is absolutely polished for smooth cycling during snap-over on the fatter Grendel cartridge rims-another custom feature I've never seen on factory AR15s covering the past 4 decades of studying the AR15 market inside and out. The bolt is marked "MP" indicating Magnetic Particle inspection, has a very deep black sheen to it, and has other features to it I'll let LaRue keep close to the vest that are important for reliability with the 6.5 Grendel cartridge. I can tell right away that somebody has been paying attention and did more than their due diligence in ensuring this rifle would be ideally set up to feed and function on 6.5 Grendel as if the AR15 was meant to run on 6.5 Grendel all along. Inside the receiver set, I notice that the aircraft grade aluminum parts were first anodized in FDE, then Cerakoted FDE over this. This allows the internal critical dimensions for the FCG and bolt carrier raceway to be controlled tightly, unlike Cerakote applied inside, which will gall against the carrier rails and cause sluggish operation of the BCG. Again, we see attention to detail in not only aesthetics, but critical processes, alloys, dimensions, and overall execution of a combined symphony of master craftsmanship in the CNC and injection-molding era. Moving forward, the Stealth 2.0 upper/handguard fit is perfect when looking at the upper receiver rail and handguard rail. You have to look for the seam to confirm that they are 2 separate pieces if you look at the rail from the rear and try to find the interruption. The handguard is very lightweight and slim profile, with a feel in the hands that promotes pointing and carrying. Looking under the handguard, you see that there is something different going on with the gas system at the gas tube/gas block junction. There is a little ferrule that seals the gas tube into the low profile gas block, preventing gas leakage common to many other factory rifles. Firing the Stealth 2.0 Grendel with several different types of ammunition, (to include a slower-burning propellant hand load that generates higher port pressure) showed no signs at all of any leakage from this area. The functional result is that you have a very consistent gas system circuit, leading to consistent carrier inertia and reliable cycling right out of the gate. On personal custom builds, I have attempted to mitigate this issue with adhesives, but have still seen leakage. Not so with the LaRue Stealth 2.0 Grendel. Finally, at the muzzle, the Tranquillo muzzle brake is perfectly timed to Top Dead Center. It has some unique features that appear to aid in mounting and keeping a square muzzle device arrangement, and also has 4 flats on its base circumference. The included barrel nut wrench has flats for this muzzle device as well, with specs etched onto the wrench-another indication of a level of attention to detail not seen in this market. I got the package with the FDE Cerakoted LT-104 scope mount and Burris 1.5-6x MTAC optic. The LT-104 matches the finish of the rest of the rifle perfectly, and I would love to see this option for ordering LT mounts in the future. The rifle was shipped with 2 magazines, 1 an Elander 17rd smooth black enamel-coated with smooth white follower, and 1 5rd CProducts mag. On my initial range trip, I was shocked at how smoothly and effortlessly this rifle handles and cycles. Having built and test-fired countless 6.5 Grendel AR15s, I have to say that this rifle cycles so smoothly, it reminds me of a tuned .223 Wylde race gun shooting 55gr loads, and I was shooting 120gr and 123gr factory and hand loads. With the 6x Burris MTAC, I was able to hammer 5rd group after 5rd group into tight clusters at 100yds, everything within 1.5 MOA of the original POI of the test group Mark shot with the rifle. What was scary was how the first group printed dead-on where Mark's test fire group was, and I got the rifle and optics in separate shipments! I will follow-up with a more in-depth accuracy analysis once I've mounted a higher magnification optic, but so far, the rifle is very consistent and easy to hit POA with, even when rapid-fired, without losing sight picture. As shipped, I could have taken the rifle out immediately and filled tags, or cleared small steel plate racks. The reticle does not move more than 1.5" off the target under recoil (there's hardly any recoil at all), and I was shooting off a shaggy carpet range block since I forgot my bipod at home. Having built so many different AR15s and 6.5 Grendel AR15s, I honestly have to say that I've never had one of them turn out like this one when looking at how perfectly it cycles in that happy window of AR15 cyclic rate. I'm guessing it has to be somewhere around 700rpm, which is a sweet spot really. Ejection was right around 3:00 to 4:30 as best as I could tell with the range net, and all my brass came out without any damaged rims. Firing pin indentations were almost perfectly concentric with the primer, indicating excellent bolt alignment with the bore. All in all, this rifle has made me realize that if I ever want a 6.5 Grendel, LaRue is at the top of the list. It's like a custom-built rifle with tools and techniques available to the custom shop that small shops simply don't have. When you realize that LaRue designed and built every major component from butt plate to the muzzle, there is no competition I'm aware of with that capability. This rifle is a custom shop production rifle really, for a price at least half of what you would normally pay for half the features. This is truly my new favorite 6.5 Grendel.
****************************************


Anyway..... I took the Grendel to the range today to break in the barrel and zero my scope. This is some of the conclusions I've come to.

First off pulling the charging handle to rear doesn't feel like "glass riding on oil" more like wiping your ass with shards of glass!! The charging handle that was supplied in the kit has a rough textured anodize finished and so does the upper receiver so until those two break-in it's not a pleasant feeling.

The upper receiver and handguard do come together nicely but far from seamless..

After a quick cleaning I began sighting in my Razor Gen 1 and conducting Barrel Break in using wolf gold 120 grain ammo.. shot one and cleaned for 5 rounds, and locked in my Zero.

I shot my first 5 round group with the wolf gold 120 grain hollow point and It produced a solid 1.70 MOA group. Then cleaned again.

Next up was Hornady 123 Amax Factory ammo I conducted two 5 shot groups both of which set at 1.5 MOA, after the two five round groups I let her cool for about 20 minutes and conducted my last cleaning for break in.

Last up was my handloads I use in my Les Baer .264,
123gr Amax, 28.2grs RamShot Tac, Horn Brass, CCI BR4 .
Shot two more 5 shot with my hand loads both groups we're at 1.5-1.7 MOA.. Grrrrrrrr

At this point I was sick and fucking tired of listening to that TWANG!! from the mil-spec buffer system. I replaced the LaRue buffer and spring with a JP Silent Captured Spring and also swapped out the LaRue M16 full Mass bolt carrier and installed my JP LOMAS carrier with the LaRue Bolt, and let the barrel cool for another 20 minutes.

I started up again with two 5 shot groups with the Hornady 123 Amax Factory ammo and the group's shrunk considerably to a solid 1 MOA.

I waited five minutes and then went back to my hand loads, again two 5 Shot groups but this time both groups sat at .5 MOA
The JP SCS and LOMAS Carrier made a huge difference in the performance of the rifle and overall pleasantry of shooting.
Just a side note all groups were shot without the provided muzzle brake and a AR gold trigger.

Overall I feel this will make a GREAT hunting rifle and extremely convenient that it likes the same Hand loads as my Les Baer .264, but definitely not something I would consider for intermediate precision shooting. I will be conducting a few more upgrades. I'll be sending in the upper receiver to my Smith to make sure the Receiver Face is true before bedding the barrel extension and installing an SLR adjustable gas block.


Oh.. MSTN If you feel like this is thread Crashing I sincerely apologize and will remove it immediately..

Jake
 
Last edited:
FWIW - LRRPF52 is pretty well known in the 6.5G community and quite literally wrote the book on the 6.5G; he's not Mark LaRue. ;)

I've not received my upper kit yet, it arrives Monday, but I have shot one of the LaRue complete FDE rifles, both suppressed and unsuppressed. It was pretty smooth shooting and that 6.5G round (as opposed to shooting some of the larger calibers) almost had me wondering if I was shooting a center fire. I also didn't recall any blowback shooting suppressed, but my evidence was only a couple of 5-shot groups.

I'm interested in your thoughts why the SCS and LMOS made such a difference in performance. I had the opposite experience with the SCS in my LaRue .260, it actually opened up the groups and I'm at a loss to try and explain how the SCS could have, for example and in my case, introduced such a lack of consistency. It was so bad, I popped it out on the range and went back to the H2. I probably should have done a bit of testing to see if there was any pattern, for example, in a round being stripped from the left or right.
 
Last edited:
  • Like
Reactions: JeffLebowski
That definitely sounds like a Mark Larue review. At first it sounded like one of his barfcom fan boys but that is way too long and detailed and filled with Larueisms to be legitimate.
 
LRRPF52 is a member here. Should be easy enough to ask him if he wrote it and end the speculation.
 
I shot a .07" 3 shot "group" with one of Gaps when I was doing sight in. Guess it's a 1/10" rifle.

3 shot groups don't count and from what I read these are .75-1.25" rifles and some have reliability issues. I was looking at the rifle deal minus the lower.


Can you link the info on the reliability issues?
 
Oh.. MSTN If you feel like this is thread Crashing I sincerely apologize and will remove it immediately..

Jake

I support your 1st Amendment rights, just as I support our 2nd Amendment rights. So what if we don't agree on everything.

Very few will agree with what I'm about to say, because it all flies in the face of conventional wisdom. Conventional wisdom is sometimes neither.

Barrel break in and load testing is something I do not enjoy doing. It is slow, tedious, and sometimes frustrating work. But, I've done it - a lot - chronographing almost every round fired in recent years on an Oehler 35P. Thanks to the chronograph input, I'm of the opinion at this point that you can't (with 100% certainty) check new load in a barrel until it's had ten rounds of that load down the barrel. Also, a barrel won't (with 100% certainty) shoot properly after cleaning until you've had ten rounds through the barrel. In simple terms, it takes ten rounds for a barrel to "settle down", i.e., have the velocity stabilize, after any changes. If the velocity isn't stabilized, how can the accuracy be expected to be?

There's no point in asking me to explain any further. Sure, we all can have our theories. I've come to terms with the fact I'm not smart enough to really be sure.

Also, conventional barrel break in techniques may be helpful with a run of the mill "factory" barrel with a roughly machined throat, but they're not productive with a quality barrel like you have in the LaRue rifle. Just peek at the chamber and throat with a borescope and you'll see what I mean. There are no offensive tool marks in the throat to "break in".

Additionally, there is no need for a anyone to attempt to square up the face of a LaRue receiver. Very few gunsmiths have equipment as comprehensive as LaRue QC does. By contrast, with most forged receivers, you can't find a single true surface against which to reference anything in the first place.

It's not uncommon in a precision gas gun barrel to see mediocre accuracy for the first 100 - 200 rounds. After that it behaves better. The culprit, I surmise, from borescope inspection every five rounds in new barrels, is the initial gas port erosion. A little irregular chunk of steel sometimes comes out at the leading edge of the gas port. This irregular spot can deeply score the bullet jacket. If you do not have a borescope, a telltale sign is a single small arc of copper, no more than 1/10", showing at the muzzle. This irregularity smooths out with use, and the accuracy improves.

Oh, here's a trick for shooting groups - Load 15 rounds in the magazine for a five round group, not just five rounds. This provides more consistent upward pressure on the bolt carrier throughout the five rounds being fired. This makes an even bigger difference in the large frame AR's than the small frame ones.


I'd be interested to see how your LaRue 6.5 Grendel upper shoots NOW for you with the original components installed. After ten rounds of the same ammo through the barrel.

 
Last edited:
  • Like
Reactions: JeffLebowski
I support your 1st Amendment rights, just as I support our 2nd Amendment rights. So what if we don't agree on everything.

Very few will agree with what I'm about to say, because it all flies in the face of conventional wisdom. Conventional wisdom is sometimes neither.

Barrel break in and load testing is something I do not enjoy doing. It is slow, tedious, and sometimes frustrating work. But, I've done it - a lot - chronographing almost every round fired in recent years on an Oehler 35P. Thanks to the chronograph input, I'm of the opinion at this point that you can't (with 100% certainty) check new load in a barrel until it's had ten rounds of that load down the barrel. Also, a barrel won't (with 100% certainty) shoot properly after cleaning until you've had ten rounds through the barrel. In simple terms, it takes ten rounds for a barrel to "settle down", i.e., have the velocity stabilize, after any changes. If the velocity isn't stabilized, how can the accuracy be expected to be?

There's no point in asking me to explain any further. Sure, we all can have our theories. I've come to terms with the fact I'm not smart enough to really be sure.

Also, conventional barrel break in techniques may be helpful with a run of the mill "factory" barrel with a roughly machined throat, but they're not productive with a quality barrel like you have in the LaRue rifle. Just peek at the chamber and throat with a borescope and you'll see what I mean. There are no offensive tool marks in the throat to "break in".

Additionally, there is no need for a anyone to attempt to square up the face of a LaRue receiver. Very few gunsmiths have equipment as comprehensive as LaRue QC does. By contrast, most forged receivers, you can't find a single true surface against which to reference anything in the first place.

It's not uncommon in a precision gas gun barrel to see mediocre accuracy for the first 100 - 200 rounds. After that it behaves better. The culprit, I surmise, from borescope inspection every five rounds in new barrels, is the initial gas port erosion. A little irregular chunk of steel sometimes comes out at the leading edge of the gas port. This irregular spot can deeply score the bullet jacket. If you do not have a borescope, a telltale sign is a single small arc of copper, no more than 1/10", showing at the muzzle. This irregularity smooths out with use, and the accuracy improves.

Oh, here's a trick for shooting groups - Load 15 rounds in the magazine for a five round group, not just five rounds. This provides more consistent upward pressure on the bolt carrier throughout the five rounds being fired. This makes an even bigger difference in the large frame AR's than the small frame ones.


I'd be interested to see how your LaRue 6.5 Grendel upper shoots NOW for you with the original components installed. After ten rounds of the same ammo through the barrel.

Im not concerned about the accuracy right now as I said above its already shooting .5 with the same loads from my other Grendel, so that's good enough for me for a hunting rifle. I will play with it back and forth with the original components and see if it was just a fluke incident, but in my experience JP Parts make everything better as long as you know how to properly adjust them.

As far as checking the receiver face, I do that with all my builds, it's nothing personal towards his equipment that's just me, it's a $25.00 peace of mind. I just know that no matter how good your equipment is sometimes a turd just slips out.

Frank White at CLE taught me about the gas hole erosion, before that I would never thought twice about that issue.

Anyway.. Thanks for the info MSTN
 
FWIW - LRRPF52

I'm interested in your thoughts why the SCS and LMOS made such a difference in performance. I had the opposite experience with the SCS in my LaRue .260, it actually opened up the groups and I'm at a loss to try and explain how the SCS could have, for example and in my case, introduced such a lack of consistency. It was so bad, I popped it out on the range and went back to the H2. I probably should have done a bit of testing to see if there was any pattern, for example, in a round being stripped from the left or right.


Did you run the H2 SCS?? Sounds like you ran the standard SCS.

Also keep in mind that the JP SCS is fully adjustable for spring tension and weight. What most people fail to realize is that this JP SCS is a three-part system, it's SCS + LOMAS BCG + AGB=Awesome..

You just got to treat every custom-build like it's your penis and you're 12 years old again.. you just got to play with it till you figure out how it works..lol
 
Last edited:
Just checking to see if anyone has any feedback on using an Omega suppressor with this rifle. I read somewhere about the TranQuilo was specifically designed to prevent any cycling issues. Rather than use the brake that came with the can I was going to try the direct thread? I'm a little leary of doing anything that could cause damage to either the AR or the can? Maybe being just a little over protective.
 
Did you run the H2 SCS?? Sounds like you ran the standard SCS.

Also keep in mind that the JP SCS is fully adjustable for spring tension and weight. What most people fail to realize is that this JP SCS is a three-part system, it's SCS + LOMAS BCG + AGB=Awesome..

You just got to treat every custom-build like it's your penis and you're 12 years old again.. you just got to play with it till you figure out how it works..lol

I ran the standard SCS and did not try the heavier springs. I'd be a bit hesitant running a LMOS (even though I have one) in the .260 as the LaRue has their PST, which is not adjustable.
 
I ran the standard SCS and did not try the heavier springs. I'd be a bit hesitant running a LMOS (even though I have one) in the .260 as the LaRue has their PST, which is not adjustable.

Order up a Heavy H2 JP SCS... And I bet you dollers to Donuts is will perform perfectly, if fact if it doesn't work I'll buy it from you. Just remember the 6.5's don't like carbine length buffer systems.. always run a full length set up.
 
Order up a Heavy H2 JP SCS... And I bet you dollers to Donuts is will perform perfectly, if fact if it doesn't work I'll buy it from you. Just remember the 6.5's don't like carbine length buffer systems.. always run a full length set up.

Thanks, but I probably won't. No sense tweaking it as it has 1200rds down the barrel and is running fine with the red spring / H2..
 
Took the Grendel out again today, just to get some more time behind her.

I started off by slow firing the leftover 30rds of Wolf 120gr and then gave her a 20min cool down.

​​​​​The results from the target below are as follows:. I used my Handloads from my LBC .264 for all of it...at 9 O'clock and Center I used the Original LaRue BCG and Buffer/Spring... At 12, 3, and 6 I used my JP SCS and LOMAS BCG, and yes Boys and Girl's the group at 6 O'clock is a 5 round group .268 MOA, the 12 O'clock wasn't to shabby either but I goober'd it up when I tried to peel the targets off the backboard, I believe it was just under .5

I think she'll be good to go for annihilating some rock chucks, next time I'll install the muzzle break and see what difference that makes. IMG_20170814_114657434_HDR.jpg
 
Last edited:
Took the Grendel out again today, just to get some more time behind her.

I started off by slow firing the leftover 30rds of Wolf 120gr and then gave her a 20min cool down.

​​​​​The results from the target below are as follows:. I used my Handloads from my LBC .264 for all of it...at 9 O'clock and Center I used the Original LaRue BCG and Buffer/Spring... At 12, 3, and 6 I used my JP SCS and LOMAS BCG, and yes Boys and Girl's the group at 6 O'clock is a 5 round group .268 MOA, the 12 O'clock wasn't to shabby either but I goober'd it up when I tried to peel the targets off the backboard, I believe it was just under .5

I think she'll be good to go for annihilating some rock chucks, next time I'll install the muzzle break and see what difference that makes.

Interesting. I'm going to try a Lantac bcg and see how it does before I order scss. Just to note I'm having similar accuracy issues as to your starting point.
 
Interesting. I'm going to try a Lantac bcg and see how it does before I order scss. Just to note I'm having similar accuracy issues as to your starting point.

Originally posted by bigjake83 View Post

You just got to treat every custom-build like it's your penis and your 12 years old again.. you just got to play with it till you figure out how it

​​​This is worth remembering...

 
Wes, others: there is a thread in the LaRue forum on AR.15, that some of the owners were not happy with the fit, at the rear between upper and lower. I see the gap on your rifle, too, Wes. Esp. Pronounced on the left side. It is like there is an AR10 pattern trying to meet a DPMS pattern. On is sharp edged and the other rounded.

is this a real issue, or just optics?
 
Wes, others: there is a thread in the LaRue forum on AR.15, that some of the owners were not happy with the fit, at the rear between upper and lower. I see the gap on your rifle, too, Wes. Esp. Pronounced on the left side. It is like there is an AR10 pattern trying to meet a DPMS pattern. On is sharp edged and the other rounded.

is this a real issue, or just optics?

Yes it is very noticeable, and quite frankly disappointing.. bottom line is he machine the left hand side Way Too Thin, it's functional but can foresee it being an issue with dirt and sand getting in easily, that's also the reason I've never liked the tOBR, it have the same issue the upper is completely disproportionate to the lower, it's obvious he just used the OBR Lower for the tOBRs.

Anyway.... This is MSTN's thread if there is nothing positive to report we should keep it to PM's please.
 
Last edited:
Received my FDE 6.5 G upper kit on Monday (ordered 8/1), put it together tonight. The upper came out to about 5.5 lbs with magpul pro sights. I swapped out the carrier for a BCM ion bond one and the CH for a Geissele. I may also swap out the brake for some thing light, but will see how it shoots first.