Grendelhunter.com - Complete 6.5 Grendel Upper

[macflyboy]

You are absolutely correct. I assumed that's what he was asking, knowing the difference. Well, now that you mentioned it, what are your thoughts?

Thanks for clarifying. I am trying to determine the effect of barrel length on rifle precision.

What I've sorted out so far is that a longer barrel increases muzzle velocity which results in (slightly) reduced wind drift and drop at range. At this point I'm assuming that any benefit from an extra 2" of barrel (18" vs 16") will be lost in the noise for my application (hunting). I am not precise enough for the extra 70 fps to make a difference.

[LRRPF52]

You normally don't see 70fps difference between 16" and 18".

[SIZE="3"]17.6" Lilja barrel:[/SIZE]
123gr Hornady SST factory 30JUN2015
2441
2467
2477
2489
2481
AVG: 2471fps

123gr Factory SST 17MAY2016 64˚F
2451
2449
2473
2456
AVG: 2457fps

120gr Scenar-L PF load
2505
2504
2532
2518
2498
AVG: 2511fps

[SIZE="3"]18.5" Lilja barrel:[/SIZE]
123gr Hornady SST factory 30JUN2015
2468
2441
2421
2495
2453
AVG: 2456fps

[SIZE="3"]16" AA/Shaw barrel:[/SIZE]
123gr Lapua Scenar Precision Firearms factory 03APR2012
2447
2451
2454
2450
AVG: 2451fps

123gr Lapua Silver Scenar Moly Factory Precision Firearms Load 90˚F
2522
2484
2582
2518
2503
AVG: 2522fps

123gr Hornady A-MAX factory 25MAY2013
2365?
2470
2422
2470
2460
AVG: 2439fps

These have all been with a Chrony Beta model, 15ft from the muzzle. The 6.5 Grendel Reloading Handbooks have a ton of data and barrel length estimator graphs.

[inthevalley]

Would be very interested to hear if these uppers are reliable with Wolf Steel Cased ammo

[pajasonc]

Would be very interested to hear if these uppers are reliable with Wolf Steel Cased ammo

Just keep in mind these are the grendel 2 chamber. I don't know if thats a bad thing or not. Some say yes some say no.

[Aged1]

We'll call this "so far so good". Got my grendelhunter upper Wednesday. I got: 22" Fluted Stainless Barrel
Medium Contour
Rifle Length Gas
1-8 Twist 5R
5/8x24 Threaded Muzzle with Thread Protector
16.5" Free Float KeyMod Hand Guard
Forward Assist - Strike Industries
Dust Cover - Strike Industries
6.5 Grendel II Chamber

Need powder, mag primers, brass, dies etc. My usual source for powder/primers has gone away (they had some ugly reviews & their prices were a little high). Big brown truck brought dies, brass, bullets (2 for now) located powder, but primers are more challenging. Brand new Dick's Sporting goods/Field and Stream opened week ago reasonably close...no primers yet, but the man took my business card, and is keeping me informed of inventory.
THEN yesterday I built some preliminary start up ammo, and found I am Cartridge OAL challenged. Can find no data on Sierra 100 grain loads, and stuck one pill in the barrel......oops. Today I have been: to Utube U on OAL in things; then Midway for all the OAL gauge items...and they even had a threaded Grendel case.
Stay tuned...oh...also.. Today new glass Vortex Crossfire II Hog Hunter... Such fun!
And and... I have made a few queries via email, of Grendel Hunter and in every case his response is superb.

[VASCAR2]

The 85 and 100 grain Sierra Varmint hollow points are pretty short blunt bullets. Western powders shows a C.O.A.L. At 2.1300 for the 85 grain Sierra varmint. I load my Sierra 100 grain varmints at 2.1500 or less C.O.A.L. in length.

[Aged1]

The 85 and 100 grain Sierra Varmint hollow points are pretty short blunt bullets. Western powders shows a C.O.A.L. At 2.1300 for the 85 grain Sierra varmint. I load my Sierra 100 grain varmints at 2.1500 or less C.O.A.L. in length.

Thanks for the help. Shooting later today. I'll try the 2.1500 number ( except that fourth place right of the decimal is outside my tooling ability ��

[KC Huntin]

Update?

[Aged1]

Any update on how it shoots??

Shooting summary on mine (22" fluted stainless, rifle gas, 1-8 twist, 16.5 key mod hand guard, and bolt/bcg) drum roll, ONE HOLE. And that's brand new bbl. the hole could get smaller with more practice. ��
Other parts of that story..100 grain Sierra varmiter with 27.5 gr of Leverevolution, not magnum primers (trying but local sources are OUT). I have varied the powder charge +|- a grain...drats...still one hole. Then shot some Hornady 123 gun eld, and still one hole.
PLUS I have sent Grendelhunter a few emails and the response is always timely, and helpful. With the last exchange he offered a unsolicited " gift". I'll keep specifics to myself to spare him unneeded requests. But even without the "gift/special treatment" I give Grendelhunter high marks. An AR expert I am not, but one hole groups make that meaningless.

[drewthebrave]

Shooting summary on mine (22" fluted stainless, rifle gas, 1-8 twist, 16.5 key mod hand guard, and bolt/bcg) drum roll, ONE HOLE. And that's brand new bbl. the hole could get smaller with more practice. ��
Other parts of that story..100 grain Sierra varmiter with 27.5 gr of Leverevolution, not magnum primers (trying but local sources are OUT). I have varied the powder charge +|- a grain...drats...still one hole. Then shot some Hornady 123 gun eld, and still one hole.

How many shots did you take? I once shot 48 shots from my Sig P6 at 10 yards into a single hole... that was about 5 inches across.

Joking aside, those results are impressive. If I didn't love building more than shooting, I'd give GrendelHunter a good look!

[Aged1]

Any update on how it shoots??

Shooting summary on mine (22" fluted stainless, rifle gas, 1-8 twist, 16.5 key mod hand guard, and bolt/bcg) drum roll, ONE HOLE. And that's brand new bbl. the hole could get smaller with more practice.
Other parts of that story..100 grain Sierra varmiter with 27.5 gr of Leverevolution, not magnum primers (trying but local sources are OUT). I have varied the powder charge +|- a grain...drats...still one hole. The. Shot some Hornady 123 gun eld, and still one hole.
PLUS I have send Grendelhunter a few emails and the response is always timely, and helpful. With the last exchange he offered a unsolicited " gift". I'll keep specifics to myself to spare him unneeded requests. But even without the "gift/special treatment" I give Grendelhunter high marks. An AR expert I am not, but one hole groups make that meaningless.

[dgunnut]

I was able to get it out to the range this weekend and put 30 rounds through it. Overall, it shot well. 4 of my 8 groups were 1" or under. A few groups that were larger were likely caused by my cleaning the barrel in between to properly break it in. And/or they could have been shooter error.

Over time I will be getting other ammo to try and getting dies so I can reload for it. I'll keep you guys posted on it as I do more.

Here is a link to the video on the first 30 rounds:
https://youtu.be/CAj3Jy21pZc

-dgunnut

So, since I posted my initial results I've been back to the range two more times. Unfortunately, something must have changed, because I struggled to shoot anything close to an inch, where before I had several groups under 1".

I have shot more of the Hornady SST (although a different lot than before), Hornady Black, and Hornady A-max. The majority of groups are now 2-3"! I first tried taking off the scope and re-attaching it, with no major improvement. The last trip I shot some handloads using 107 SMK's and IMR 8208XBR at various charge levels and the best grouping I got was close to an 1", with the rest all 2" or more.

I'm baffled by why first indications showed this to be a fairly accurate upper, but now 100 rounds later I struggle to get anything decent accuracy wise. The only thing I can think of that I changed was applying loctite to the barrel thread protector to keep it from coming loose. I can't imagine this would have an effect on accuracy...

I am planning on putting out a video in a few days with more info and showing some of the targets. I would like to think it's not the shooter, especially since during my last range trip I took along my new Savage FV12 in .22-250 and shot decent with that.

I am looking for any ideas you guys may have on things to check.

-dgunnut

[brassbrite]

Triple check every bolt, nut, barrel nut, scope mount, etc etc....

I was looking over my guns the other night and discovered that I had several scope mounts that came loose after the last outing at the range. I am always meticulous about keeping everything tight.

I guess when you shoot the head transfer can cause things to swell and contract with heating up and then cooling causing loose components. I cant say for sure that this is what is happening but I always seem to have to re-tighten things after a few trips to the range. Then they settle in and are fine.

Also make sure you break in your new barrel correctly. That will help with long term accuracy.

Interested to find out what the problem was. Let us know what you found out please.

[brassbrite]

^heat transfer

[brassbrite]

I just ordered a 20in barrel and bolt yesterday. So I am kind of interested in knowing whats going on.

[Lastrites]

I just had the opportunity to quickly look over a co-employee's 16" Grendelhunter upper he just received, the one that was on the close out sale. I noticed right off on this upper that the gas block appears slightly canted, coupled with the barrel possibly not being centered in the Strike Industry rail as it appeared to my eye. Also on that rail it uses 4 set screws to either lock the rail to the receiver or they assist in timing the rail square to the upper, doesn't appear have any lock-tite on the screws which I felt was odd as I certainly would have used it on those screws.

Bwtn the gb being possibly canted and likely the rail needing adjustment I am certain my future holds a tear down and reassembly of his upper. But I suggested to him to simply give it a complete cleaning, toss a scope and some irons on it and boresight it and we are going to run some ammo through it at the office.

Dgunnut, besides checking the obvious of loose screw/nuts and although you've only shot 100 rounds or so, do you think it's possibly you've had a build up of copper in the barrel? While a copper build up is a stretch with such a low round count, it's something to consider.

[dgunnut]

Triple check every bolt, nut, barrel nut, scope mount, etc etc....

I was looking over my guns the other night and discovered that I had several scope mounts that came loose after the last outing at the range. I am always meticulous about keeping everything tight.

I guess when you shoot the head transfer can cause things to swell and contract with heating up and then cooling causing loose components. I cant say for sure that this is what is happening but I always seem to have to re-tighten things after a few trips to the range. Then they settle in and are fine.

Also make sure you break in your new barrel correctly. That will help with long term accuracy.

Interested to find out what the problem was. Let us know what you found out please.

Good thoughts. I was planning to check all fasteners next, but need to go through it.

I laughed out loud when you mentioned "make sure you break in your new barrel correctly". I've seen advice on this topic ranging from clean after every shot for the first 100 using light grade sand paper (joking a bit of course) to never clean it...ever

I mentioned cleaning it every 5 rounds during the first 20 and people jumped all over me that I shouldn't clean it.

Definitely open to hearing what your opinion is on the topic and if anyone has hard data that shows how to break in a barrel "properly"

[dgunnut]

I just had the opportunity to quickly look over a co-employee's 16" Grendelhunter upper he just received, the one that was on the close out sale. I noticed right off on this upper that the gas block appears slightly canted, coupled with the barrel possibly not being centered in the Strike Industry rail as it appeared to my eye. Also on that rail it uses 4 set screws to either lock the rail to the receiver or they assist in timing the rail square to the upper, doesn't appear have any lock-tite on the screws which I felt was odd as I certainly would have used it on those screws.

Bwtn the gb being possibly canted and likely the rail needing adjustment I am certain my future holds a tear down and reassembly of his upper. But I suggested to him to simply give it a complete cleaning, toss a scope and some irons on it and boresight it and we are going to run some ammo through it at the office.

Dgunnut, besides checking the obvious of loose screw/nuts and although you've only shot 100 rounds or so, do you think it's possibly you've had a build up of copper in the barrel? While a copper build up is a stretch with such a low round count, it's something to consider.

Mine was also on the close out sale awhile back. I will take a closer look at it to see if the rail is not aligned or gas block is canted.

I thoroughly cleaned it between the first and second trip. Don't recall if I used a copper solvent or not. Then I cleaned just the barrel between the 2nd and 3rd range trips. I specifically used a copper solvent at that time. Similar results during both 2nd and 3rd range trip.

I'm looking at swapping the scope back to another upper shooting that upper to make sure the scope and mount combo is Ok. I have the scope in a Burris PEPPR mount with the quick detach features. I haven't had an issue with the scope and mount before, but who knows...

[mdewitt71]

Any new info or reviews?
Looking at the Grendel Hunter 18" SS upper.......

[Crusty]

Dez Arms' recommended break in procedure