AR-Stoner 6.5 Grendel barrel short chambered.

[XcountryRider]

Here's my theory the Liberty barrels have always had a smaller chamber you can find references on this forum all the way back to 2011!! Thats why they get such good velocity and those of us with them and have not been able to load our pills out as far as Paul does with his SST's. That said we don't need to because we get awesome velocities in fact probably the fastest of any Grendel barrels. The more bullets go through the more it sort of opens as it breaks in. When the OP could not load factory AA then that set off a panic with folks measuring and other folks fanning the flames of panic.

[Tedward]

I just measured a box of 123gr factory Hornady A-MAX for raw COL. Every cartridge was 2.250"-2.252". The ogive might be slightly different than the SST though, since I am able to load the 123gr A-MAX longer than the SST.

I made a dummy 123gr SST round, and tried it in my AA barrel, as well as a Satern 18" Grendel barrel. I can load it to 2.253" where it will just kiss the forcing cone. It chambers and extracts without force.

I also tested my long-loaded 123gr A-MAX in the Satern chamber, and no issues...chambers and extracts without force. That's a 123gr A-MAX at 2.275".

Are the barrels new or used? I think the issue is the new barrels that have not been broke in. My used Liberty barrel lets bullets drop in and out and the bolt closes with no issue.

[XcountryRider]

Are the barrels new or used? I think the issue is the new barrels that have not been broke in. My used Liberty barrel lets bullets drop in and out and the bolt closes with no issue.

BINGO!!! The fact the OP polished his barrel and it "fixed" the "issue" shows that its basically a break in thing.

[LRRPF52]

All the resources I have seen discuss the cannelure as a crimping groove. It seems to have the fringe benefit of helping the jacket retain more lead mass in the rear of the bullet after expansion in tissue.

I wonder if the Interlock was inspired by this, combined with the gilding metal jacket. Either way, it shouldn't be buried beneath the neck.

Are the barrels new or used? I think the issue is the new barrels that have not been broke in. My used Liberty barrel lets bullets drop in and out and the bolt closes with no issue.

They are used barrels, and factory ammunition dropped into them without issue when they were new, then fired, extracted, and ejected no problem. There hasn't been a "break-in" period with my barrel for reliable chambering of a wide variety of ammunition. Even the PPU 123gr SP factory ammo ran through my 16" Grendel.

[XcountryRider]

All the resources I have seen discuss the cannelure as a crimping groove. It seems to have the fringe benefit of helping the jacket retain more lead mass in the rear of the bullet after expansion in tissue.

I wonder if the Interlock was inspired by this, combined with the gilding metal jacket. Either way, it shouldn't be buried beneath the neck.



They are used barrels, and factory ammunition dropped into them without issue when they were new, then fired, extracted, and ejected no problem. There hasn't been a "break-in" period with my barrel for reliable chambering of a wide variety of ammunition. Even the PPU 123gr SP factory ammo ran through my 16" Grendel.

I have 3 Liberty barrels and just traded one so have had four barrels. They break in but that can be accelerated with a fire lapping kit. Remember i was thinking about doing that with my Liberty barrel to reduce the ES? I wonder if someone had an issue with a new AA barrel taking measurements of the COAL before a single shot was fired and broken it? I wonder how the comments would have been like then?

[cory]

I have 3 Liberty barrels and just traded one so have had four barrels. They break in but that can be accelerated with a fire lapping kit. Remember i was thinking about doing that with my Liberty barrel to reduce the ES? I wonder if someone had an issue with a new AA barrel taking measurements of the COAL before a single shot was fired and broken it? I wonder how the comments would have been like then?

If that would have been the case Bill A would of asked to have the barrels sent back to him for inspection days ago. XCR you know I've called out AA when it was deserved, but I'm also going to give credit where credit is due. I've seen Bill A. take back a "Grendel" barrel that was riddled with problems and replaced it with one of his at no charge.

[PigOPs]

I have 3 Liberty barrels and just traded one so have had four barrels. They break in but that can be accelerated with a fire lapping kit. Remember i was thinking about doing that with my Liberty barrel to reduce the ES? I wonder if someone had an issue with a new AA barrel taking measurements of the COAL before a single shot was fired and broken it? I wonder how the comments would have been like then?

It would be irresponsible not to do some safety checks BEFORE you ever fire a new barrel. It factory ammo will not chamber there is an issue. I have no doubt whoever is at fat will remedy the issue but it seems to me that you refuse to believe there is an issue... Possibly because of the two group buys that you've recently organized.

[Grendanimal]

I wonder if the Interlock was inspired by this, combined with the gilding metal jacket. Either way, it shouldn't be buried beneath the neck.

Exactly. Cannelure or not, my red flags would have gone up anyway with how deep it was seated, even with the understanding that certain bullets need to seat deeper.

I have stayed out of this thread for quite a few posts because no matter if this is an issue with a barrel, a reamer, an ammunition manufacturer, a combination of things, or none of the above, people will do whatever they feel they want to do no matter what.

Without intentionally ruffling feathers, I have read enough in this thread to know that even IF there DEFINITELY WERE defects in ANY product and I'm not saying that there definitely are in this case, or just tolerance issues on any end, there would be a lot of people who would be cognitively dissonant, and sit there doing things and trying things to ease the pain of how long they waited to complete something. That is understandable if you know humans, but is not acceptable. Once again, I am not taking "sides" on anything. I am simply saying that if it was any gun part, car part, airplane part, etc., that people have a way of doing things that make them feel better about things, which is natural, but not normally a good idea. I have my own ideas on this issue, but I will definitely know more tomorrow when I test another barrel. I am glad there are still people looking at this objectively and fairly without, what I think, involving emotions.
This is a great forum.

[LRRPF52]

I always take COL measurements when developing a load, especially as I reference the data from the manufacturer when working with a new cartridge.

When seating the bullet, you need to know how deep it will be going into the case. Standard reloading practices begin with determining your maximum COL. To assume that any of us were doing otherwise makes me question what is going on here. COL is one of the most important data points that everyone I know references and keeps firmly in mind when loading.

I just pulled out some 2009 data written in my rifle-specific notebook where I log what I have done with the firearm from a reloading standpoint. My load data includes COL with each different projectile, and they are not all the same. This is basic reloading 101, finding your COL with each projectile.

[BjornF16]

Thanks for clearing up that the purpose of the cannelure is not for crimping or an issue if set behind the end of the case as stated by a few people.

Just for clarification...the grooves on solids (e.g. GMX and X bullet) are not for crimping. The ridged cannelures on leaded bullets like SST are for crimping.

Since the 123 SST was designed specifically for the Grendel, one would expect that the cannelure would be correctly lined up for crimping. For other bullets not designed specifically for the Grendel, they may or may not line up correctly.

[Grendanimal]

I always take COL measurements when developing a load, especially as I reference the data from the manufacturer when working with a new cartridge.

When seating the bullet, you need to know how deep it will be going into the case. Standard reloading practices begin with determining your maximum COL. To assume that any of us were doing otherwise makes me question what is going on here. COL is one of the most important data points that everyone I know references and keeps firmly in mind when loading.

I just pulled out some 2009 data written in my rifle-specific notebook where I log what I have done with the firearm from a reloading standpoint. My load data includes COL with each different projectile, and they are not all the same. This is basic reloading 101, finding your COL with each projectile.

Yup. Exactly. And doing that long enough will tend to cause a person to pause when something doesn't seem right, which is why we are here trying to figure it out, no matter if there is or is not something wrong.

[Tedward]

Has anyone checked a new Lilja barrel yet???

[Tedward]

Just for clarification...the grooves on solids (e.g. GMX and X bullet) are not for crimping. The ridged cannelures on leaded bullets like SST are for crimping.

Ok, didn't read the last post like that so clearer....SST's, yes on the cannelers, end of case position, crimped or not.
It all seems not to be an issue going in my barrels that has been fired. More checking tomorrow and this weekend on the new and old. Got my go/no-go gauges, Hornady split case and OAL gauge. Now I can put everything to use finally.

[Aaron_S]

Has anyone checked a new Lilja barrel yet???

I don't have any SST ammo or bullets, 123gr AMAX factory ammo and 123gr AMAX, Nosler CC and Sierra SMK bullets.

Factory AMAX 1.678" to ogive, OAL 2.251".

AMAX bullet touching the lands/throat measured with Stoney Point OAL gauge, 1.767" OAL 2.336".

I can drop the factory round in the chamber with no bolt and even push it in with my finger and there are no markings on the bullet and it just drops back out. I would expect that based on my measurements. The barrel is not mounted yet.

My barrel is chambered for the Maxim bolt. I have a Tactical Ammunition bolt with .135" recess and I can rotate it closed by hand with the factory round in the chamber.

I'm not sure how useful this is, but its all I can provide.

[Grendanimal]

Aaron_S, which comparator insert are you using for your "to ogive" measurement, please? If it is the Hornady comparator, there is "A, B, C, D, or E"...unless you drill your own with an F blank.

[Aaron_S]

Aaron_S, which comparator insert are you using for your "to ogive" measurement, please? If it is the Hornady comparator, there is "A, B, C, D, or E"...unless you drill your own with an F blank.

http://www.midwayusa.com/product/261048/...4-diameter

[XcountryRider]

I don't have any SST ammo or bullets, 123gr AMAX factory ammo and 123gr AMAX, Nosler CC and Sierra SMK bullets.

Factory AMAX 1.678" to ogive, OAL 2.251".

AMAX bullet touching the lands/throat measured with Stoney Point OAL gauge, 1.767" OAL 2.336".

I can drop the factory round in the chamber with no bolt and even push it in with my finger and there are no markings on the bullet and it just drops back out. I would expect that based on my measurements. The barrel is not mounted yet.

My barrel is chambered for the Maxim bolt. I have a Tactical Ammunition bolt with .135" recess and I can rotate it closed by hand with the factory round in the chamber.

I'm not sure how useful this is, but its all I can provide.

Is it me or is that really long????

[Grendanimal]

http://www.midwayusa.com/product/261048/...4-diameter

My mistake. I was thinking headspace inserts..I've had a long day.

[woohoo]

Are you assuming that the bullet is usually at full diameter out to well beyond the nominal seating depth? I think only poorly designed round nose bullets have that feature. So a bullet diameter freebore gives lots of room for alignment grief, especially when manufacturing tolerances are considered. The gentle taper you see in the SAAMI spec gives a mechanism for the slop resulting from those tolerances to be minimized.

One of the results is that the bullet need NOT touch the lands to be well-centered. The accuracy enjoyed by many Grendel shooters who use factory ammunition or handload without loading to the lands testifies to this. Further, the accuracy lasts long enough that folks frequently enjoy more than 5,000 (yes, five thousand) shots before accuracy starts to slip from order .3 MOA to .6 MOA. LRRPF52 is one of these folks so we should expect that he has a pretty good handle on what makes the Grendel tick.

It really is time to re-read Page 8 and following in Volume 1 of the Grendel Reloading Handbook.

Absent that and other documentable information, we will continue to talk past each other.

Sorry I don't think the Grendel reloading handbook can compare to Precision Shootings Reloading guide http://www.amazon.com/Precision-Shooting...1931220123 where most of the top benchrest shooters in the world contributed to the book. I've been designing wildcats and reamers since 1982, read Precision Shooting mag while in print and a lot more on 6mmBR.com than barfcom. Everyone has an opinion but there are no benchrest barrels made with a compound throat. As long as my old school chambers with normal freebore will shoot Hornady 123gr Amax factory into 1/2 MOA and chamber I think I'll stick with the benchrest thought on chamber designs.
This is how normal freebore looks. Now imagine just the cone part of that starting where the mouth of the case is. If only the ogive of the bullet is sticking out of the case the bullet will lay on the bottom part of the angled cone unless the bullet is seated close enough to the lands to hold it up in line with the bore. I don't have time to draw it out on autocad but I'll try to find a drawing of it.

[JASmith]

Sorry I don't think the Grendel reloading handbook can compare to Precision Shootings Reloading guide http://www.amazon.com/Precision-Shooting...1931220123 where most of the top benchrest shooters in the world contributed to the book. I've been designing wildcats and reamers since 1982, read Precision Shooting mag while in print and a lot more on 6mmBR.com than barfcom. Everyone has an opinion but there are no benchrest barrels made with a compound throat. As long as my old school chambers with normal freebore will shoot Hornady 123gr Amax factory into 1/2 MOA and chamber I think I'll stick with the benchrest thought on chamber designs.

Woohoo, you have made the most concise summary of the controversy surrounding the Grendel chamber!

It is what it is, the accuracy is superb for most purposes, including some very competitive long range shooting. But, to my knowledge, the cartridge was not designed as a serious bench rest item.

The Grendel reloading handbook makes no pretense about what constitutes bench rest chamber design. It does, however, discuss why the Grendel chamber is as it is. Your comments above suggest that it is possible you have not looked at the relevant chapter.

I also searched for the term "bench rest" in the more than 7,000 threads in this forum. Guess what? I couldn't find a thread that talks about bench rest shooting as a competitive sport. The Grendel is not a bench rest cartridge, nor was it designed as one. It does, however, regularly show better than the 1/2 MOA you indicated when used by good shooters.

You will also see a number of posts in this and other threads that recognize the fact that design features that make a cartridge a top bench rest cartridge also tend to cause reliable function problems in the AR15. And yes, I suspect that there are very few AR15 rifles in the top levels of the bench rest world. There is a reason for that.