AR-Stoner 6.5 Grendel barrel short chambered.

[JASmith]

Prove its not SAMMI spec and stop assuming.

I assume the reference is to the liability issue. In this case, the burden will be to prove the rifle chamber was made to the spec. The debate in this thread alone has raised that question. Should something untoward happen to one of these rifles, the manufacturer will need to prove the chamber was created to spec. Since there are a lot of these barrels now floating around, checking undamaged barrels should be a straightforward exercise for the plaintiff.

If the manufacturer cannot prove the barrel was manufactured to the spec, he bears a fiscal liability along with all those who said the practice was OK. No assumptions needed.

[XcountryRider]

I assume the reference is to the liability issue. In this case, the burden will be to prove the rifle chamber was made to the spec. The debate in this thread alone has raised that question. Should something untoward happen to one of these rifles, the manufacturer will need to prove the chamber was created to spec. Since there are a lot of these barrels now floating around, checking undamaged barrels should be a straightforward exercise for the plaintiff.

If the manufacturer cannot prove the barrel was manufactured to the spec, he bears a fiscal liability along with all those who said the practice was OK. No assumptions needed.

Which is the same for all manufactures. Thousands of Liberty barrels have been used for years with these dimensions.

[Lead Chucker]

Can we compare measurements in our barrels with the recommended COL in the load handbooks?

In the present case, both Hodgdon and Alexander Arms load data recommends a COL of 2.200" for the 90 gr TNT in the Grendel.

Yes i can compare with the handbook, im not taking sides here either way. People are asking for measurments to see if the new cut throats are something new or a have been a on going thing so I measured with a standard. I used the same bullet with all three barrels keeping eveything the same. The numbers dont lie, they speak for themselves. The lighter bullets have more of a difference than the longer bullets such as the 123gn SST and AMAX. I only saw a difference of .010" between the barrel with the 123gn AMAX and SST. The two Stoner barrels have a shorter throat than my Satern cut barrel. I do understand that no two barrels are the same, and im not saying the Stoner/Liberty barrels wont work or shoot well, they have been for a few years now with the short throat. All I was saying was the Stoner barrel from over a year ago has a short throat the same as ones cut a month ago and ones being cut today. Im not taking sides either way, im just posting the numbers that I measured. You guys can argue over the rest as long as you want to. Im going to keep the Stoner barrel I got for my dad and shoot it.

[BjornF16]

Which is the same for all manufactures. Thousands of Liberty barrels have been used for years with these dimensions.

"Prove they are all the same and stop assuming"...

I think y'all all need to chill and wait for information from Satern...finger pointing, accusations and questions of under whose authority things have been done just seems like pettiness at this point.

This is how the 123 SST fits into my SATERN Spartan barrel...slight pressure pushing the bullet; had to use dowel to push bullet out of chamber.

So if Liberty barrels have the cannelure buried in the case; and SATERN barrels have the cannelure extending beyond the case, then SATERN is doing something different between the two "lines" of barrels. (Different reamer dimensions; or just level of polishing/roughness).

Let's wait for Steve Satern to weigh in on the differences and whether they are both "in SAAMI spec".

BTW: before anyone says "but you've broken in your barrel"...I just checked 129 SST again and compared to when my barrel was a virgin; no difference.

[dammitman]

ok, i want to ask this question. has anyone checked their bolt? i have a simple dial caliper. you can open it up to use the other end to measure depth. i also have a new stripped bolt from les baer. when i measure the depth of that bolt i get .136. now doing the same thing with the bolt that came with my barrel, i get .128. i know its minor but it is what it is. is this anything?

[jurassic]

I asked this question also, but from what I was told by Frank at Maxim it's not quite that simple. The length of the locking lugs need to be taken into account. I'm sure someone on here can explain it better than I can.

[rickOshay]

Here's my take on this:

1. There is something different about Liberty barrels.
2. Satern is aware of this and is proud of the higher velocities these barrels get.
3. This higher velocity is why XcountryRider likes them and why he started the Group Buy.
4. Higher velocity results from higher pressure.

So what is different? Is it a rough finish that can be lapped or shot out?
Is it due to a non-SAAMI dimension ?

Those who have Liberty barrels, especially those who have "fixed" them, should watch their velocity. Is it higher than published ? Does it stay higher after 100 rounds?

XCR - are you still getting the same velocities?

[Lead Chucker]

I asked this question also, but from what I was told by Frank at Maxim it's not quite that simple. The length of the locking lugs need to be taken into account. I'm sure someone on here can explain it better than I can.

This is correct. I measured my bolts last night also. The bolt that came with my satern barrel 3 years ago measures .135" if measured from between the locking lugs and .139" if measured from the top of the lugs. The bolt that came with the 16" Stoner barrel measures .135" from anywhere on the bolt face. Not arguing anything here just giving numbers. Im not pointing fingers at anyone. I love Satern barrels, I have one grendel and one Blkout from Satern and both are shooters! I do wonder why my Satern barrel has a longer throat than the 16" Stoner that came from the same place and reamed by the same reamer dimensions. I can see if one is polished and laped and one is not, thats fine just asking. Hopefully Satern will come back with a answer that will explain it all.

All this being said, I did notice while checking the OAL on the bullets where they first meet resistance or just touch I believe is not the lands. I believe it is touch in the free bore or the compound angle of the throat. When I first felt them touch, I could push the bullet on in quiet a bit before it would stop completely. That in my satern barrel and the Stoner also.

[XcountryRider]

This is correct. I measured my bolts last night also. The bolt that came with my satern barrel 3 years ago measures .135" if measured from between the locking lugs and .139" if measured from the top of the lugs. The bolt that came with the 16" Stoner barrel measures .135" from anywhere on the bolt face. Not arguing anything here just giving numbers. Im not pointing fingers at anyone. I love Satern barrels, I have one grendel and one Blkout from Satern and both are shooters! I do wonder why my Satern barrel has a longer throat than the 16" Stoner that came from the same place and reamed by the same reamer dimensions. I can see if one is polished and laped and one is not, thats fine just asking. Hopefully Satern will come back with a answer that will explain it all.

All this being said, I did notice while checking the OAL on the bullets where they first meet resistance or just touch I believe is not the lands. I believe it is touch in the free bore or the compound angle of the throat. When I first felt them touch, I could push the bullet on in quiet a bit before it would stop completely. That in my satern barrel and the Stoner also.

Right thats what i've been saying i load my SST to 2.265in not the 2.2 that people are quoting without actually clambering a real round. They are assuming that they are touching the lands when they are not.

[rickOshay]

And just so everyone knows where I'm coming from, I LOVE my 24" cut-rifled Satern barrel:



And yes, it has a different chamber OAL than the Liberty I just bought. And it gets lower velocity than XCR's Liberty barrel (see his video).

[XcountryRider]

Here's my take on this:

1. There is something different about Liberty barrels.
2. Satern is aware of this and is proud of the higher velocities these barrels get.
3. This higher velocity is why XcountryRider likes them and why he started the Group Buy.
4. Higher velocity results from higher pressure.

So what is different? Is it a rough finish that can be lapped or shot out?
Is it due to a non-SAAMI dimension ?

Those who have Liberty barrels, especially those who have "fixed" them, should watch their velocity. Is it higher than published ? Does it stay higher after 100 rounds?

XCR - are you still getting the same velocities?

I'm getting 2590fps from my 18in barrel with SST loaded to 2.265in with 30.8gr of CFE223. Hornady lists the high load at 31.2 for CFE. Its also a accurate load. Hundreds of round have been sent down the barrel and not sure how many because i'm not counting.

[rickOshay]

I'm getting 2590fps from my 18in barrel with SST loaded to 2.265in with 30.8gr of CFE223. Hornady lists the high load at 31.2 for CFE. Its also a accurate load. Hundreds of round have been sent down the barrel and not sure how many because i'm not counting.

That velocity is significantly higher than reported by BWild97 and BjornF16, and they used more CFE. See Handbook Vol 2 p89

[Sputnik]

Right thats what i've been saying i load my SST to 2.265in not the 2.2 that people are quoting without actually clambering a real round. They are assuming that they are touching the lands when they are not.

Ah, I get it now! The little mark visible just forward of the casing/cannalure on these lower three pictures of factory 123 Amax and SST rounds, and the other four marks that evenly spaced around the rest of the circumference are caused by the Free Bore and Compound angle of the Throat. Thanks for clearing that up.

[Lead Chucker]

I will take a old piece of brass tonight and load a dummy round and check the stoner barrel with a Amax and a SST to see what happens.
I do know that the measurments I took last night with the Amaxs in my satern barrel are not to the lands. I do load longer than that, and im not in the lands. I load 123gn Amaxs to 2.260" with 28.7gn of 8208xbr (I know thats over the max load by .2 tenths but its accurate with no pressure signs) in my 18" Satern. I now use CFE instead of XBR though. Thats why I think that first kiss you feel when the bullet touchs isnt the lands. Just my 2cents.
I did sleep at a Holiday Inn last night also!

[BluntForceTrauma]

The lands look like they are shallow from the start because of the compound throat. Seems like the slight gradual engraving of the bullet won't have much of an effect on pressure. If factory loads will extract without being sticky and too much engraving into the bullet it doesn't seem like a big deal to me. If the bullet is close or kisses the lands slightly isn't that what the chamber is designed to do.

It seems to me that this is actually the correct technical answer. I'm assuming the compound throat was designed around Bill A's original favorite load, the 123 Lapua Scenar. The challege was to then shoot with reasonable accuracy the VERY wide range of 6.5mm projectiles available (part of the beauty of a 6.5).

You could even say the 6.5 Grendel SAAMI chamber is DESIGNED to headspace on the very shallow first angle of the compound throat. Understandably, this is CONFUSING to those who have heard all their shooting lives: "Don't jam into the lands! Don't jam into the lands!" In standard throats this is prudent advice. A compound chamber upends the conventional wisdom.

I think the concerns of those trying to learn are valid. But both Satern and AA know and knew what they are doing. Satern, for example, takes pride in very precise measurements, in having a "line-to-line" fit of bullet to barrel, so I'm guessing they will seem a hair tighter (and shoot a bit faster).

Let the newer shooters simply understand that a slight kiss into the lands of the shallow first angle of the compound throat is both per spec and is OK with the SAAMI 65G chamber.

John

P.S. Knowing the various personalities and agendas involved in this thread, there JUST might also be a titch of pot stirring, as well.

[Tedward]

Hanka, Thanks for your post. Another knowledgeable persons explanation is appreciated.

Almost got to 400 post to finally hear from you, have you been out of town or just reading and grinning???

[Lead Chucker]

It seems to me that this is actually the correct technical answer. I'm assuming the compound throat was designed around Bill A's original favorite load, the 123 Lapua Scenar. The challege was to then shoot with reasonable accuracy the VERY wide range of 6.5mm projectiles available (part of the beauty of a 6.5).

You could even say the 6.5 Grendel SAAMI chamber is DESIGNED to headspace on the very shallow first angle of the compound throat. Understandably, this is CONFUSING to those who have heard all their shooting lives: "Don't jam into the lands! Don't jam into the lands!" In standard throats this is prudent advice. A compound chamber upends the conventional wisdom.

I think the concerns of those trying to learn are valid. But both Satern and AA know and knew what they are doing. Satern, for example, takes pride in very precise measurements, in having a "line-to-line" fit of bullet to barrel, so I'm guessing they will seem a hair tighter (and shoot a bit faster).

Let the newer shooters simply understand that a slight kiss into the lands of the shallow first angle of the compound throat is both per spec and is OK with the SAAMI 65G chamber.

John

P.S. Knowing the various personalities and agendas involved in this thread, there JUST might also be a titch of pot stirring, as well.

I think you are spot on!

[Sputnik]

So does this mean everybody is right? It may touch the lands a bit, but it is safe to shoot without danger or excessive stress on components anyway? That is acceptable, but I am still interested in hearing what Satern's says next week.

[rickOshay]

There are two types of people - those who say:

Wow - higher than normal velocity! Where do I get one?

And those who say...

Whoa - there's no free lunch. Higher velocity means higher pressure.


Are the pressures unsafe? No problems reported.
How high are they? No one has measured.

Lesson learned: know your chamber, even if you don't reload.

[NugginFutz]

Let the newer shooters simply understand that a slight kiss into the lands of the shallow first angle of the compound throat is both per spec and is OK with the SAAMI 65G chamber.

John

First, let me say "Thanks!", Hanka, for clearing the air, here.

I've been reading this board for about a year, and an active participant for the last 6 months, or so, and I guess that makes me one of the "newbies". With that understood, let me say that I am astonished to read this for the first time, today.:confused: I've read about the compound chamber, and how it differs from the .264 LBC, on a few occasions. I cannot recall, however, reading where it was indicated that the Grendel is intended to be seated to the point of contact within that forcing cone. If I missed it somewhere, I profusely apologize for going off "half-cocked". Going forward, I will pay closer attention.

I would say that this factoid needs to be enshrined in a sticky, somewhere within the board's reloading section, and I further submit that it should be prominently mentioned in any subsequent 6.5 Grendel reloading literature. It's saddening to see how much energy was needlessly expended on this debate.

P.S. Knowing the various personalities and agendas involved in this thread, there JUST might also be a titch of pot stirring, as well.

Ya think?