The MRGG barrels will work in the previous LT Large Frame Rifles. The aluminum upper receivers will form around the new MRGG barrel extensions, but the Previous barrel and not compatible because you're going Steel to Steel.
-
Having trouble using the site?
Contact support
New Rifle from LaRue - the MRGG-S 6.5 Creedmoor
- Thread starter RedBreast21
- Start date
The MRGG barrels will work in the previous LT Large Frame Rifles. The aluminum upper receivers will form around the new MRGG barrel extensions, but the Previous barrel and not compatible because you're going Steel to Steel.
Cool, look forward to seeing your thoughts on it.
Looking forward to seeing your groups + thoughts
So Mark personally test fires every rifle and signs the target. So he shoots one goofing off group, 1 I'm kinda serious group, and 1 "real" group?
But you got 3 groups from ML himself, for the price of 1! That's a deal
3 shot groups lol... wonder how many of those test targets go in trash before he finds one that can ship.
Apparently, they shoot so many that they’re saving paper by shooting the targets multiple times. Looks like they shoot until they get a good one, then annotate the groups afterward- for the lolz.
Here you go...
Something new worth mentioning, LT seems to have changed receiver extension..
Best I can shoot it this weather...
Absolutely no failures suppressed and unsurpressed. When I got home I noticed the Ventum was loose, that's why the groups opened up with the can.
Absolutely no failures suppressed and unsurpressed. When I got home I noticed the Ventum was loose, that's why the groups opened up with the can.
No it definitely has its Pros and Cons that I'll get into when I write up the review, and those are cherry picked groups. Next range trip hopefully wont be in the middle of a dust storm, I'll shoot a 5x5 which will give a more realistic accuracy eval.
One issue I will discuss is the Upper and Lower have quite a bit of slop between them and Larue has changed thier barrel blanks.
Larue barrels now have Polygonal Rifling. A few months ago one of my Range Buddies bought one of those 16" Larue .308 barrels from Dvor and has been having issues with it since the beginning, when I bore scoped his barrel I noticed Poly Rifling but didn't think much of it at the time because it was a $200 barrel so I wasn't expecting much anyway.
All the other Larue barrels I have on hand have the traditional Button Cut style that we've seen for the past several years.
Well now I’m going to bore scope the 16” 308 I recently built. It’s also one of those optics planet Larues. 8 Twist mid gas. Didn’t have any issues though. Shot pretty good during break-in.
The slop is surprising to hear. Very surprising. They like em coming out of Leander tight. I've felt some so snug on a hot day, you couldn't separate them.
Look forward to your write-up.
I just ordered an 18” LaRue 6.5 Creedmoor Stealth barrel from optics planet. Hopefully it will shoot well
I took a gamble on one of these because the profile & config was exactly what I wanted for a low mass suppressed Creed.
FYI - Optics Planet description is wrong. Barrel config is even better for my purpose. Barrel is 18", 7.5T, .750" gas journal, but gas system is Rifle + 2", I ordered the XL gas tube from Larue.
Also FYI - My barrel was short chambered i.e. no-close on Go Gauge. Would not chamber factory Prime 130. I tried JP, RCA, & Toolcraft bolts. Larue CS is worthless, so I just ordered a Clymer finish reamer + pilots from Brownell's ($160ish) & fixed it myself. Now Go + .001".
Only one range trip so far. Shot the Prime 130 @2610 IIRC & 5/8", Berger 130 @ a couple fps faster 2617 I think & .75", My 130 OTM hand load in crap brass @2740 & under 1/2". I came home from the range & ordered a second barrel. Just received the second one today.
Not trying to shit on Larue here, aside from the HS issue, their barrel impressed me. Larue large frame mags are tits. I just like building my own rifles to suit personal taste/purpose.
@bigjake83 - I'm curious how the MRGG will perform for poi shift bi-pod to bag? I'd expect it to do well.
I've got 100 Lapua SRP prepped & plan to shoot a positional shift test this weekend. Very pleased with how it turned out. Larue parts are Barrel, gas tube, & mags. Rail is 16-3/4" SOLGW M89HA, BKF ambi receiver set, Dark Hour extension, PWS ratcheting castle nut, Imod Clubfoot, Wilson/BCM grip, JP LOMOS/HP bolt/SCS, Geissele NM/Super Charging handle, Battle arms Pro 60 degree ambi safety, Aero Adj gas block
MaxRGG
Without mag/Can/Bipod wt is 12 lbs 2 oz & right at $2100 all in rifle only. That includes the reamer/pilots.
Factory Prime 130 @ 2610
Hand load 130 otm @2.820 oal CCi #34 RL 15.5 = 2740fps no work up. This was my bolt gun load backed off .8gr
I want to Thank you for this Information. My plan is a lighter DMR type than my KAC 20” 6.5. Need a strong light fore end for this now
That's actually one of the topics I will be touching on, with the previous models you can thermo fit the barrel into the receiver but due to the design of the Steel SAMS Incert that doesn't seem to be a option.
The New barrel extensions and slightly undersized at 1.176" at the face of the barrel extension and 1.178" at the base. Standard diameter barrel extension are generally around 1.184"
I called and spoke with Dave at LT for more clarification about the two tenion detents that are build into the SAM unit, he stated the purpose of them is to create the same effect of thermo fitting by applying upward pressure onto the bottom of the barrel extension.
Dave couldn't give me a specific torque spec so I've just snuged them up to a point that I feel comfortable I'm not going to strip the screws.
At the recommended 40ftlb barrel nut torque the barrel has a fair bit of flex. I've increased the barrel torque to 55ftlbs and it seems to have increased the rigidity I'll try several different torque specs to see if it has any bearing on performance or accuracy.
Also keep in mind with the free floating barrel design and the new steel SAMs insert their theoretically shouldn't be much shift if any at all. The Sams unit is definitely securely installed.
man when they said the Sam adapter took a tapered barrel extension…..I assumed it tapered larger to smaller from front to rear, and sort of sat inside of it like a cone. But it’s the opposite. PERHAPS…. .mil program required the barrel to stay retained in the receiver even if the barrel nut was removed??
Also very interesting on the poly rifling.
Any thoughts on their new gas block?
Shot (4) 5-rnd groups all with Hornady 140 ELD Match, seems to be consistent.
doesn't seem to shoot as tight with the suppressor on, still no malfunctions.
doesn't seem to shoot as tight with the suppressor on, still no malfunctions.
What's the best shooter you have in your stable? In 6.5CM.
That's a tough question, if I had to pick one as I Do It All rifle I'd go with the 18" Bartlein OBR.
Consistent Sub Half MOA Accuracy, Compact, and built like a Tank.
Jake.
Seems like the newer LaRue's have a hard time getting under half minute with greater than 3 shot groups.
Great posts in this thread. Reinforces my thought about avoiding an LT upper for the LT 762 lower I have sitting around.
Great posts in this thread. Reinforces my thought about avoiding an LT upper for the LT 762 lower I have sitting around.
Keep in mind that's with Hornady Factory 140 Match ammo. If I was to work some handloads up I'm 100% sure i could get it under 1/2 MOA.
And the the above OBR has a 18" Bartlein Barrel in it, turned by one of the best barrel smiths in the country.
The Bartlein OBR has me thinking I should get a barrel from whoever uses their blanks.
I've been meaning to add to this thread for an update, I've been doing my very best to give the LaRue MRGG a fair chance and I was about to throw in the towel and just write it off as a .75 - 1 MOA rifle until the other day when I discovered the issues for The Unexplained Flyers and poor accuracy.
I've been feeding it nothing but a solid diet of Hornady 140 grain ELD Factory ammo, I was running some tests with various other cartridges that seem to chamber a bit on the tight side when I discovered that when chambering the Hornady 140 ELD Factory ammo the bullet was actually sliding forward anywhere between 5-9 thousands. This would definitely explain inconsistent accuracy.
Since I've already put 200 rounds down the barrel, I've decided to start Handloading, with a bushing die that will shrink the neck down 5 thousands under loaded neck diameter.
After loading 80rds of 140 and 147 ELD's in Lapua brass I chambered a bunch of them by loading one round in the magazine and let the bolt release go, slamming the rounds into battery.
None of my handloads moved from their original COAL.
This should resolve the erratic flyers and inconsistent accuracy.
I'll be starting a new thread, deep diving into all the fine details of the MRGG and it's performance. At this point I can't really complain about much, I did however place a order for a Custom 6.5CM Bartlein for it just to see how good it can get.
The LT MRGG comes stock with a 20" Rifle Length +2 Gas System. Right now I'm kicking around the idea of doing a 6.5CM Bartlein in a 16.5" with rifle Length Gas system for a nice lightweight compact package.
I'm not interested in doing yet another .308 as my Predatobr already has two. If anyone has any recommendations or something they'd like to seen done, let me know I could also do a 16.5" 6CM as well.
I've been feeding it nothing but a solid diet of Hornady 140 grain ELD Factory ammo, I was running some tests with various other cartridges that seem to chamber a bit on the tight side when I discovered that when chambering the Hornady 140 ELD Factory ammo the bullet was actually sliding forward anywhere between 5-9 thousands. This would definitely explain inconsistent accuracy.
Since I've already put 200 rounds down the barrel, I've decided to start Handloading, with a bushing die that will shrink the neck down 5 thousands under loaded neck diameter.
After loading 80rds of 140 and 147 ELD's in Lapua brass I chambered a bunch of them by loading one round in the magazine and let the bolt release go, slamming the rounds into battery.
None of my handloads moved from their original COAL.
This should resolve the erratic flyers and inconsistent accuracy.
I'll be starting a new thread, deep diving into all the fine details of the MRGG and it's performance. At this point I can't really complain about much, I did however place a order for a Custom 6.5CM Bartlein for it just to see how good it can get.
The LT MRGG comes stock with a 20" Rifle Length +2 Gas System. Right now I'm kicking around the idea of doing a 6.5CM Bartlein in a 16.5" with rifle Length Gas system for a nice lightweight compact package.
I'm not interested in doing yet another .308 as my Predatobr already has two. If anyone has any recommendations or something they'd like to seen done, let me know I could also do a 16.5" 6CM as well.
Last edited:
I don't have a request, but I have a possible recommendation. My .260 PredatOBR didn't like 140 bullets (140 Berger hybrids in my case). I switched to Berger 130 AR Hybrids and it loved them. I was not alone - many on the old .260 PredatOBR thread on another gun website arrived at the same conclusion. A slight decrease in BC, but 130s are easier on the system and unless you're shooting past about 1250, the difference will be close to insignificant.
I'm not a fan of Hornady bullets (other than the 750AMAX). Sierras, Bergers or Lapua (or Barts, of course).
The bullet weight isn't the problem, it was the fact that the Hornady 140 ELD Factory ammo was extending its COAL upon chambering causing inconsistent accuracy.
Good way to get around the bullet slippage problem in semi autos is
When you set up resizing die, make it full length size but not expand the bullet/case mouth area. As long as you chamfer the case mouth and use Boat Tail bullets the bullet will expand the case mouth and provide enough tension without a crimp
Been doing this for years. If I feel a loose seat it becomes a fouler round. Worked through eight years international f class doing this
I have Norma .223 that’s light on neck tension, so it’s not wholly unique or unknown.
Similar threads
