Grendel II chamber

[Trock03]

Midway - Grendel II

Just noticed that the Stoner barrels are back up at Midway but this time they specify Grendel II in the title and technical info. Of course they don't specify what a Grendel II is or why it's exists.

I would be curious to know their response to an inquiry as to why their Alexander Arms uppers and Shilen barrels have Grendel chambers yet the budget Stoner barrels have Grendel II chambers. The II implies an improvement (although there is not reason to improve a correctly cut/finished chamber).

As a person who rolled the dice and ended up with a short-chambered AR Stoner barrel in January (returned it and went with another brand) I'm a little annoyed by this. Though, in the end, if it gets more people shooting the Grendel it's better for all of us for obvious reasons.

TC

[nincomp]

There is information about the Grendel II here :

http://www.65grendel.com/forum/forumdisplay.php?30-Grendel-Based-Wildcats-and-Variants

[Whelenon]

They should've called it the 264 Saturn. When Les Baer Customs made changes to the Grendel chamber at least he took ownership of it, 264 LBC.

[Sputnik]

They should've called it the 264 Saturn. When Les Baer Customs made changes to the Grendel chamber at least he took ownership of it, 264 LBC.

Thank you! I agree +1000!

[Agshooter]

Stoner Barrel from Midway - Grendel II

I read through the Grendel II thread, but honestly, I think some of it is over my head.

Bottom line, if I handload and want a hunting rifle, is the Stoner Grendel II barrel OK?

http://www.midwayusa.com/product/479866/ar-stoner-barrel-and-bolt-ar-15-65-grendel-grendel-ii-chamber-medium-contour-1-in-8-twist-18-stainless-steel?cm_vc=ProductFinding

[VASCAR2]

If it were me I'd pass with this barrel fiasco from the last batch. These barrels may be from that batch and had the chambers reamed.

I have two friends buy 6.5 Grendel Barrels from Brownell's which are $289.99 and currently out of stock but you can back order. I checked both these barrels and bolts. Both were in spec and from the way the first shoot's I'd say the second will also be a shooter. Another option for a cheaper 6.5 Grendel barrel would be J&T Dist. Or maybe Blackhole weaponry which uses polygonal rifling and 264 LBC chamber.

[heinz57grendel]

All of your loads charges and their seating depths will have to be adjusted according to the length of your chamber. I am dealing with this same issue and after talking to mark at precision firearms this weekend at the nra convention, I am going to send my satern barrel off to him to have the throat fixed. My powder charges and seating depths are different from most of all the other info on here. You will be doing your own R&D just as I am doing now. Buy a true grendel chamber.

[Whelenon]

I don't like what Saturn is doing with the Grendel II and I would think twice about buying one of their barrels. That said, for hunter it should be fine but I would highly recommend measuring the chamber for each bullet to determine your max COL. Even without all the Grendel II BS, I've been measuring my chamber as part of my reloading SOP.

[zbay]

Please pardon my ignorance on this subject I've never really got into the technical details of chambers, and throats. I understand that different guns like different ammo and perform better with said ammo. In your opinion will the Grendel II not run factory ammo as advertised? Do you think the modifications made by Saturn will effect accuracy or long range capabilities?

[JASmith]

This should at least partly help answer your question:

stokesrj, whose opinion I deeply respect, has shot both chambers extensively, and if I recall his old posts correctly, he has found that both chambers shoot well, provided you select the best bullet for that rifle.

If you want ULTIMATE accuracy with any barrel, you have to work the load and bullet correctly.

I believe that the compound throat allows you to shoot more bullets with reasonable accuracy, as LR1955 has pointed out. Bill Alexander and Arne Brennan did a lot of work to find that chamber and for good reason. At one point I shot every single factory load into sub MOA groups with a SAAMI chamber. I suspect that I could repeat that with my SAAMI Grendels now.

I already know that I can't do that with the LBC 264 Black Hole barrel I have, but it does shoot factory Hornady into sub MOA groups and my handloaded Hornady into .75 MOA groups as well. I doesn't like my handloaded 107 Sierras, or 100 grain Bergers. It also won't shoot 123 Lapua Scenars, but that fits what Arne stated above.

Note that the lighter, shorter bullets don't do as well in the LBC and we can infer the same will be true of the "Grendel II" because both have the parallel freebore. That is part of the reason the compound throat exists -- to shoot ALL bullets reasonably well. That 0.5 degree taper in what would normally be a parallel freebore makes a big difference in accuracy when shorter bullets are loaded while still doing very well with the heavier bullets.

These differences mean very little if one is looking for minute of deer.

In the end, know what you are buying or have already bought and develop your expectations accordingly.

[Bwild97]

zbay

In your opinion will the Grendel II not run factory ammo as advertised?

Factory Ammo "should" operate normally in this sub-standard chamber according to the descriptions provided by Saturn.

Do you think the modifications made by Saturn will effect accuracy or long range capabilities?

I would not believe this chamber to be a boon nor a deficit to the 6.5 Grendel cartridge in terms of performance. Quality materials and manufacturing practices are key elements in long range accuracy.

[NugginFutz]

The Geetoo should perform on par with the .264 LBC, and be able to digest any factory ammo. How well it shots depends on what ammo you run through it. My .264 LBC had to be worked fairly hard to get the 123 AMax happy, which eventually ended up shooting well. As I'd previously described, the margin of error was rather small. I recall bwaites having a similar experience with his.

Bottom line is that if you want to eek out the best performance from one, you may have to work at it, as I have. Am I satisfied with my shooter? Absolutely. This BHW polygonal barrel has proven very accurate and stupid easy to clean. Will a Geetoo do as well? I'll never know, but that is another story. Is my .264 better than a Grendel? Perhaps with one or two pills, but I would have to work it, whereas most of the Grendel factory ammo just shoots well through a Grendel's compound throat with little fuss.

Just my .02

[Agshooter]

So it sounds like the GII is no worse or better than the Grendel chamber, and similar to LBC. So why all the uproar? If it was "I bought a barrel expecting X chamber and received Y" I get that.

Other than that, i dont see the issue. Am I missing something?

[JASmith]

So it sounds like the GII is no worse or better than the Grendel chamber, and similar to LBC. So why all the uproar? If it was "I bought a barrel expecting X chamber and received Y" I get that.

Other than that, i dont see the issue. Am I missing something?

If you are referring to current factory loads with 120 grain and heavier bullets, then you got the gist of it!

One more time, the challenge will be getting the same tight groups with 100 gr and lighter bullets with the "GeeTo" as one gets with the SAAMI chamber. There seems to be plenty of evidence to form and support that conclusion.

[rickOshay]

So it sounds like the GII is no worse or better than the Grendel chamber, and similar to LBC. So why all the uproar? If it was "I bought a barrel expecting X chamber and received Y" I get that.

Other than that, i dont see the issue. Am I missing something?

It will be interesting to see if the GeeToo will meet the accuracy of the LBC - given the difference in neck diameter.

My understanding is that one of the reasons the LBC is accurate is because of the tighter neck (@ 0.295) versus the SAAMI 6.5 Grendel (@0.300). The GeeToo has BOTH the wider neck and the parallel lead. So centering the bullet on the bore will be challenging. Again, my understanding is that you would need a high quality barrel to make up for mis-aligned bullets in the chamber. Not going to get that for $200.

Again - it will be interesting to see range reports once people finally get them and shoot them. So far, there's been a great deal of "keyboard claims".

Likely it will be a decent shooter and let people seat long projectiles further out as claimed. And they will likely get another 50 fps higher velocity - see my Post #23 of this thread.

But lesson learned is that if you want a 6.5 Grendel - check with the barrel supplier to confirm that it's SAAMI spec, including the throat. If you want something else, specify that too. People thought they were ordering a SAAMI Grendel, and got something else instead.