Grendel II chamber

I still at a loss as to why Satern has created this hysteria.Make a friggin 6.5 saami spec Grendel and be done with it.I have one of their 20" barrels and its a machining masterpiece.Again excuse my ignorance for even bringing this up.So honestly where does our alligence for Satern lie as a horde? Possibly sending a "horde" letter if it hasn't been done yet to solve the shlit show.A lot of pull comes from members and internet forums for a hell of a lot of gun related product.Ignore if an attempt has been made.
We have extreme cases on both sides of the fence,but honestly the whole deal makes me want to go drink myself stupid.

[rickOshay]

Much Ado about Nothing

This recent drama over throat dimensions has been, in my opinion, Much Ado about Nothing.

The recent debates have been over various opinions about the dimensions of the throat of chambers the 6.5 Grendel. I really don't want to rehash the arguments about throat dimensions. I just want to try to put things into some perspective. So I am providing an EXAMPLE of what that might look like.

The recent drama has resulted in the commercial production of yet another Grendel variant - the Grendel II. My understanding is that the driver behind it was to have a longer throat than the SAAMI 6.5 Grendel in order to seat long-for-caliber bullets farther out of the case.

Now there has also been a debate as to whether this new variant is an answer to a question not being asked, because the SAAMI 6.5 Grendel can handle bullets up to the 156 gr Lapua Mega. This was done by Lapua, one of the contributors to the development of the SAAMI 6.5 Grendel. Moreover, the primary medium sized game that the Grendel is well suited to take can be easily handled with projectiles weighing 125 gr or less, and fit nicely into the 6.5 Grendel compound throat. The need for these large projectiles really is questionable. What advantage to they bring?

But the idea of getting more powder in the case for the long bullets is an intriguing one. So how much more powder is it really?

A recent post (#412) by Mark at Precision Firearms recounting a discussion with Dave Kiff at PTG says the Grendel II is the same as the .264 LBC-AR. (http://www.65grendel.com/forum/showt...returns/page42what does moving the bullet 0.1" further out really get you in the way of more powder?

Well, if you evasion the bullet moving forward 0.1", then a void would be created behind the bullet with the dimensions of 0.1" long by 0.264" in diameter (for a flat base bullet to keep it simple, boat tails would actually be much less). The volume of that void would be calculated by:
volume = pi x radius^2 x height
volume = 3.14 x 0.132^2 x 0.1
volume = 0.00547 cubic inches

How much powder will fill the void of that volume?

The density of CFE 223 is 15.957 grains per 1 cc.
- 1 cubic inch is 16.387 cc's.
- so 0.00547 cu in is equal to 0.089 cc's

So the amount of CFE 223 that would fill 0.089 cc's is 1.4 grains (15.957 x 0.089).

So the longer chamber would enable one to add 1.4 grains more per case.

What does that get you? About 30 - 50 feet per second higher velocity depending on the bullet.

What does that mean to the hunter? About 30 yards longer hunting reach. Hunting reach is here defined as the distance at which the bullet drops below is minimum recommended velocity for proper expansion.

YES - there is measurable advantage for a subset of 0.264 projectiles available to the reloader if a longer chamber is used.

I will put forth that the average hunter will not be able to see any real world advantage here.

And I'll repeat - these longer bullets are not needed to take most game folks are going after (see 6.5 Grendel Reloading Handbook Volume 2 and http://shootersnotes.com)

Again, so much drama and energy spent on negligible benefit.

[rickOshay]

The "Confused and Misrepresenting" will not claim the Grendel II is a SAAMI 6.5 Grendel. They are now using a nonsensical term of "SAAMI Compliant". Sort of like saying "almost pregnant".

If the throat does not have a 0.5 degree taper, it's not a SAAMI 6.5 Grendel.

They are widely claiming that the taper is what is wrong with the Grendel, hence the Grendel II name to draw comparison to the 6.8 SPC saga. The implication is that the SAAMI chamber is bad and needs fixing. Pure marketing hype and internet hysteria.

The Grendel II is an answer to a question not being asked. Just another way to try to damage the image of the SAAMI 6.5 Grendel - which is the ultimate goal of these folks.

[Walter]

Go there nugginfutz. The throat is part of the chamber. Take a look at the print. How could it not be. SAMMI is there to make sure the cartridge will fit in the chamber.

[BjornF16]

so if a go and no go gauge fits exactly the same as in the grendel and grendel II chambers how is the second one not a grendel chamber and acceptable to SAMMI?? its been repeated to we are blue in the face there is NO spec for throat length. I disagree how the how liberty deal was handled by them. but having a different throat option in my mind is a good thing. being able to always seat out to at least mag length is a great thing. If accuracy was proven in the grendel II I would honestly rather have that chamber. so far its not been proven yet.

A go/no go gauge does not measure the Leade/Throat...only the case chamber.

The Grendel go/no go gauges fit .264 LBC, 6.5 CSS, etc. It doesn't mean these are Grendel SAAMI spec any more than a .223 Wylde chamber is the same as .223 Remington or 5.56 NATO (also all using the same go/no go gauge).

I'm not sure who is repeating until "we are blue in the face" about the throat, but the throat is just as much a part of SAAMI spec as is the chamber...whomever is telling you this is grossly mis-informed. Just look at the SAAMI drawing for minimum chamber and you will see the throat dimensions specified.

[NugginFutz]

so if a go and no go gauge fits exactly the same as in the grendel and grendel II chambers how is the second one not a grendel chamber and acceptable to SAMMI?? its been repeated to we are blue in the face there is NO spec for throat length. I disagree how the how liberty deal was handled by them. but having a different throat option in my mind is a good thing. being able to always seat out to at least mag length is a great thing. If accuracy was proven in the grendel II I would honestly rather have that chamber. so far its not been proven yet.

But the spec DOES cover the throat. And THAT has been repeated and proven in several places. Please, don't make me go back in that bad place, again. The info is there for anyone who really wants to know.

[bwaites]

so if a go and no go gauge fits exactly the same as in the grendel and grendel II chambers how is the second one not a grendel chamber and acceptable to SAMMI?? its been repeated to we are blue in the face there is NO spec for throat length. I disagree how the how liberty deal was handled by them. but having a different throat option in my mind is a good thing. being able to always seat out to at least mag length is a great thing. If accuracy was proven in the grendel II I would honestly rather have that chamber. so far its not been proven yet.

There IS a spec for throat length, what has been repeated and repeated does not make it truth. Dave Kiff considers the throat part of the spec, as does AA, Hornady, Lilja, Precision Firearms, etc. Only Satern has stated that it isn't.

The SAAMI Grendel chamber has a .5 degree cone into the throat, in comparison to standard throats which have a 1.5 degree.

The go/no go gauges also work for the 6mm AR, the 20 Grendel, etc. They only determine headspace, the point on the shoulder where the datum is.

I can seat all the regular Grendel Bullets out past mag length in my Satern Cut Rifled Grendels. There is plenty of room to do so. I can seat 130 Bergers out there too. For single loading, I've run the Bergers out to 2.32 COAL.

[cory]

Read (gag) here, if you can stomach going back through it. I have to go wash my mouse...

http://www.65grendel.com/forum/showt...ll=1#post83844

I need a stiff drink after reading that **** again. I say again, but I don't recall that post. I may have missed it the first time. I recall a mention of a JGS reamer before now, so I likely missed it. Either way. :/

[hidesert cowboy]

so if a go and no go gauge fits exactly the same as in the grendel and grendel II chambers how is the second one not a grendel chamber and acceptable to SAMMI?? its been repeated to we are blue in the face there is NO spec for throat length. I disagree how the how liberty deal was handled by them. but having a different throat option in my mind is a good thing. being able to always seat out to at least mag length is a great thing. If accuracy was proven in the grendel II I would honestly rather have that chamber. so far its not been proven yet.

[NugginFutz]

I thought it was a PTG reamer they were using from the beginning. My information came from reading this forum and following the great Liberty S**T Show of 2014, so it may very well be completely incorrect.

If it wasn't a PTG reamer would you provide the source for that information, please?

Read (gag) here, if you can stomach going back through it. I have to go wash my mouse...

http://www.65grendel.com/forum/showthread.php?7828-AR-Stoner-6.5-Grendel-barrel-short-chambered.&p=83844&viewfull=1#post83844

I did call Satern 3 weeks ago to ask if they could lengthen the throat on two Stoner barrels and keep the compound throat...just lengthen it. I was told they would ask and find out and call me back. I have not heard back. Im not bashing Satern, I have a rifle cut 18" that shoots great. And although these Stoner barrels have a some what short throat they are very accurate.

[cory]

I do believe this particular reamer has been around awhile. There has been so much hearsay that we need to be careful not to lose sight of the facts:

1) The reamers used by Satern on the Liberty (short-throats) were NOT made by PTG.
2) Dave Kiff at PTG helped Satern rectify the problem with a reamer that he says: a) has been is used for 2-3 years and b) he will personally guarantee to outshoot the conventional Grendel chamber.

(Note: I am not agreeing/disagreeing just want the facts to be stated clearly)

I thought it was a PTG reamer they were using from the beginning. My information came from reading this forum and following the great Liberty S**T Show of 2014, so it may very well be completely incorrect.

If it wasn't a PTG reamer would you provide the source for that information, please?

[bwaites]

It is critical that people actually contact those with whom they are doing business!

The solution of "scraping" the throat is not one that I would have foreseen from Satern, but if members are happy with it, I feel like it is one solution.

BUT...the board exists to help members, and not to hammer on anyone for their decisions or business practices. Satern has made thousands of Grendel barrels, and until this last episode with the Liberty barrels, I had heard very few complaints! I have two myself, and they are great barrels.

Work with whoever made your barrels, and try to work something out between you that is satisfactory to both, please!

Internet scandal is all to easy a trap to fall into. Lets not create ill will where none is necessary!

Pfff no thanks! however I do appreciate the fact that Mark is willing to do that.Getting everything set up and concentric to the chamber and bore once its already been cut can be a chore.

Contact mark at PF…. think it is $75? and he will use a finish reamer to fix it...