Any interest in the 6.5 Grendel?

[Creature]

I am nearly ready to start a new AR15 build. This time, my interest has turned to the 6.5 Grendel.

Intending it to be a multi/general purpose rifle, I am looking at 20" barrels as I am very comfortable shooting my A4-based 223-wylde competition rifle. I am thinking something much like this:



Any advice, experiences (pros/cons) and/or words of wisdom regarding barrels, bolts and anything else 6.5 Grendel would be greatly appreciated.

Pics too, if ya got 'em!

 

[justin22885]

i used to be interested in the grendel, but really not anymore, theres just too much compromise that has to be made because one type of bolt will have weak locking lugs prone to breakage while your other option is a weak extractor prone to breakage.. on top of it the magazines are also a compromise as the AR magazine well is just too narrow to fit a true double column magazine with 11.35mm based cartridges

277 wolverine still interests me though, out of the same barrel lengths itll put out as much energy as the grendel, the 110 grain .277 bullets have a ballistic coefficient of like .370 which is about as high as 70+ grain 5.56 bullets, and it pushes these at 2500fps... you get much higher ballistic coefficient and velocities than 7.62x39 for a much flatter trajectory while retaining the same amount of barrier penetration while impacting with even more energy down range

 

[Creature]

too much compromise that has to be made because one type of bolt will have weak locking lugs prone to breakage while your other option is a weak extractor prone to breakage..

Could you elaborate further on these two points, please? I knew that early bolts were reamed out which made for weak lugs and extractors, but newly designed dedicated 6.5 bolts had, I thought, corrected these growing pains issue.

 

[fireman 9731]

I looked into doing a Grendel build. I'm still interested but its on the back burner right now.

I think the supposed issues with weak bolts is over stated, as well are the magazine problems. Who has actually had problems? I couldn't find any.

I was interested in the longer barrels. 22-24 inches. A lot of people have shorter ones for hunting though. The Grendel really shines at longer ranges. And the cheap Wolf ammo for plinking is always a plus.

But then I started pricing components and things starting adding up. Then I heard the idea of using a CZ 527 action for Grendel build and that got my attention.

I still like the cartridge, its very efficient, and would be great in a smaller package.

 

[Creature]

277 wolverine still interests me though, out of the same barrel lengths itll put out as much energy as the grendel,

Looking at the numbers, it looks to me like the 277 Wolverine comes very close to the 6.8 SPC in speed and performance, both of which don't hold a candle to the 6.5 Grendel's performance out beyond 400 yards. Since I am looking for performance out past 600, what the 277 Wolverine offers is definitely not something I am be interested in.

 

[Jackal]

I was looking into the 6.5 and the 6.8 very heavily. My decision? I got a 7lb .308 AR10. I just couldnt see the practical benefit of either cal over the .308, aside from ammo weight.

 

[Llama Bob]

The 6.5 Grendel is just a bad design, due to the bolt and extractor issues mentioned above. The bolt face is simply too big for the platform. There are also substantial magazine/feed problems.

The right solution if you want to shoot 6.5mm (or better yet maybe heavy 6mm) in an AR15 is probably to base it off the SPC case. Unfortunately that's still in the realm of wildcats since the shoulder needs to be set back sufficiently for long bullets. But in 6mm especially the performance should be excellent and free of the reliability problems the 6.5 Grendel has.

 

[Creature]

Interesting...the Grendel has been tested for full-auto and did well. And please substantiate your claim about bolt issues?

 

[Llama Bob]

Are you familiar with the difference between Type 1 and Type 2 Grendel bolts & chambers? You can either have locking lugs that break or extractors that break. There is no "it actually works right" option.

 

[Creature]

Is this the issue you had in mind regard bolt types?

 

[Llama Bob]

That's the issue, but it misses the point that the Grendel configuration they label "GO" is actually "MAYBE" because it has bolt lug failures.

 

[Creature]

So are you saying that this issue has no resolution that fixes both problems?

 

[rayatphonix]

Creature, there are many, many AR Grendels out and about. Have there been problems, sure, but I would say for every problem reported there are hundreds of happy users. Given the increased potential of a failure this might not be my choice for something I'd take into battle, but for hunting and paper it will most likely last a lifetime.

Mine is about 3 years old and has had zero issues and I have no concerns about its reliability. I'm happy enough I'll soon have a bolt action version.

 

[Creature]

I agree. The 6.5 would make a good perimeter rifle whereas
I would use the 5.56 for inside of 400.

 

[rayatphonix]

As I read the graphics it seems that if the chamber is cut for a .135 rim and the proper extractor is used, there isn't an issue.

 

[Creature]

Apparently the lugs remain an issue if I understand Llama Bob correctly. If I am not mistaken, he is saying that you can fix one issue but not the other. I am having trouble understanding why.

 

[Llama Bob]

So are you saying that this issue has no resolution that fixes both problems?

Not that I know of. There was some talk of special materials or heat treat for the bolts, but I don't think it ever really solved the problem.

 

[justin22885]

The 6.5 Grendel is just a bad design, due to the bolt and extractor issues mentioned above. The bolt face is simply too big for the platform. There are also substantial magazine/feed problems.

The right solution if you want to shoot 6.5mm (or better yet maybe heavy 6mm) in an AR15 is probably to base it off the SPC case. Unfortunately that's still in the realm of wildcats since the shoulder needs to be set back sufficiently for long bullets. But in 6mm especially the performance should be excellent and free of the reliability problems the 6.5 Grendel has.

even the SPC case is a compromise, the AR-15 was designed so tightly around 5.56 that you cant really do much of anything without one compromise or another, any cartridge larger than 5.56 is going to be more of a staggered column than a double column and give you a reduced capacity in relation to the length/weight of the magazine, and even the 6.8 SPC had to be loaded to lower pressures so not to exceed the bolt thrust limitations of the bolt

and thats why 277 wolverine can come so close to it, due to using a smaller case head it can be loaded to a full 62kpsi safely and make up for some of what it lacks in case volume

 

[Creature]

Keeping a second bolt handy seems prudent then.

 

[fireman 9731]

Please, show me all of the broken Grendel bolts.

 

[crazysccrmd]

Are you a reloader? If you are, you can get a number of 6.5 variants based on the 6.8SPC case. An easier option is to load the 6.8 with 130gr Berger Classic Hunter. Launched at 2600fps from a 16" barrel it bests Hornady factory 6.5G (2580fps/24" barrel) in a more compact package with stronger bolts.

 

[barnbwt]

IIRC, wasn't there a fad around the time Grendel was introduced of overloading it in a misguided attempt to reach low end 308/Creedmore levels? Had to do with folks wanting a 'pocket 6.5 Swede' which was tempting with the long-ogive bullets that do well at long range.

I'm sure this had nothing at all to do with the initial instances of bolt failure. Same with how normal 223 bolt failures from aftermarket sources were totally unheard of over the course of the last 8-year panic cycle, with not a single company scrimping on quality/inspection, or experimenting with more widely available materials that didn't end up panning out.

TCB

 

[barnbwt]

I've become recently enamored with the Grendel since it's among the better propositions for getting a long-ogive bullet out of an autoloader that isn't a full-size rifle. First started looking into it when I heard Kel Tec would supposedly do an RDB bullpup in grendel; struck me as a super-low-rent WA2000 in concept (accurate med-long range bullpup autoloader).

I can't stand the AR, personally, so my ambitions lie with the RDB, or elsewhere, and the 'concerns' (read: fear mongering) over the bolts and magazines don't worry me as much. Biggest issue with Grendel is supposedly ammo, but I think the proliferation of 223/9mm has caused US shooters to lose their sense of perspective on the issue. Considering it's built off of common components much like Blackout, it won't be going away anytime soon (though it may not be rocketing to dominance, either)

TCB

 

[Llama Bob]

even the SPC case is a compromise, the AR-15 was designed so tightly around 5.56 that you cant really do much of anything without one compromise or another, any cartridge larger than 5.56 is going to be more of a staggered column than a double column and give you a reduced capacity in relation to the length/weight of the magazine, and even the 6.8 SPC had to be loaded to lower pressures so not to exceed the bolt thrust limitations of the bolt

and thats why 277 wolverine can come so close to it, due to using a smaller case head it can be loaded to a full 62kpsi safely and make up for some of what it lacks in case volume

All fair points. All I was getting at is that the SPC case family at least leaves enough bolt to run reliably. There is a fair argument that the bolt thrust problem is fatal to trying to hotrod the platform. I won't really disagree.

It's also worth noting that the M262mod1 trajectory is pretty good. Unless you're trying to improve terminal performance it's not clear that hot rodding is buying much.

 

[Jimster]

I was interested until now.