Two chamber sizes

[noone]

Neither of the two rifles I have (one from Lothar Walther, and one from Alexander Arms) has the cartridge stamped onto the barrel. I had to have that done after I received the rifles.

Both the barrel I received from Lothar Walther, and the rifle my friend received from Lothar Walther are .007 shorter than my Grendel from AA, and his 6.5 CSS from Sabre Defense.

So, yesterday I spoke with Dave at Pacific T&G, and we have decided to get a finish chamber reamer and have both of the short chambers opened up by .007 thousandths. Although sending the barrels back to Lothar Walther is an option, that idea was rejected as Woody is a bit testy whenever anyone even suggests that there may be an issue with quality control. So I don't even want to waste the time listening to him tell me I am wrong.

Both the Lothar Walther barrels were made about the same time, and although they shoot well, I'm not interested in shortening the expensive Lapua brass by overworking it so often. My AA barrel also shoots well, so it just made sense to open up the chamber of both the Lothar Walther barrels.

Considering the problems associated with discussing quality control with Woody, possibility of having the uppers disassembled to have the chambers reamed out by Woody, the expense of shipping and insuring both uppers, the time waiting for the uppers to come back, reassembling, then re-zeroing both rifles, buying a reamer and having the chambers opened up was a much more attractive option. Besides, then I'll have a 264 LBC/AR finish reamer for future use if necessary.

Infidel470 and I are going to split the cost of the reamer, and deal with the short chamber issue ourselves. A side benefit is that after the chambers are opened up .007 thou, both of the rifles will have fresh throats in them. Both of the rifles have around a thousand rounds, maybe two thousand through them, so the fresh throat will be a side benefit.

It is largely irrelevant to us what spec drawing Hornady, AA, or LBC shows for specs. The fact remains that two of us have Lothar Walther barrels with chambers that are .007 shorter than our other rifles in this cartridge..by whatever name you choose to call the cartridge (Grendel, 6.5CSS, 264 LBC, 6.5/6mmPPC improved).

As both Infidel470 and I have Lothar Walther barrels that are .007 shorter than the Alexander Arms, and the Sabre defense chambers, logic says that either two chambers have to come down in size (impossible) or two chambers have to be opened up to reduce the expansion/sizing down work on the expensive Lapua cases. Hence our decision to buy a reamer and have the chambers opened up.

[philmurphy]

The reason why Grendel chambers work is because they are GRENDEL chambers. That is the way they were designed and that is why they work with 6.5 Grendel ammunition. The problem with your chamber is that it is not a 6.5 Grendel and ant prudent owner of a weapon should only use the ammo that id stamped on the barrel. It is not BA's fault that you bought a barrel that is not a 6.5 Grendel and he owes you nothing. I suppose that I would be bitter too if I bought a rifle for which no ammo exists( especially if I did not posess the skills necessisary to reload) and would do everything in my power to put the blame on someone else rather than blame myself for my own mistake.

Rasp,

You obviously did not read or understand what I wrote. My barrel was made by Lothar Walther. LW has made more 6.5G barrels than any other barrel maker(source Woody Woodall, President of LW.) They made them, from the beginning for Arne, and they made them for AA. LW continues to make 6.5G barrels and they know how to chamber a 6.5G barrel.

Where did I write that BA was responsible for my barrel not chambering Hornady 6.5G ammo? Are you aware that there is an AA chamber drawing with a .295 neck? BA calls it his "bolt match" chamber.

I am not seeking to "put the blame on someone else." It is clear from your writing that I have more technical information on 6.5G/6.5ETC chamber evolution and problems, than you do. I suggest that you read my posts carefully. You might learn something.

Phil

[philmurphy]

As both Infidel470 and I have Lothar Walther barrels that are .007 shorter than the Alexander Arms, and the Sabre defense chambers, logic says that either two chambers have to come down in size (impossible) or two chambers have to be opened up to reduce the expansion/sizing down work on the expensive Lapua cases. Hence our decision to buy a reamer and have the chambers opened up.

Noone,

Before you ream, you may want to verify that your cartridges are headspacing on the datum. I tested Hornady 6.5G ammo, in a L.E. Wilson cartridge gauge and found that it was headspacing on the neck to shoulder radius. As a result the ammo measured .001 - .002 over the max of 1.2251. Hornady measured my ammo and confirmed the results. Hornady has reduced the length of their headspace to 1.217. That is under the min of 1.2201. Hornady has not changed the neck to shoulder radius. Interestingly, Lapua and Prvi Partizan make the radius correctly. I was told by an individual familiar with case forming, that a sharper radius would require an extra die and process, resulting in increase cost. Hornady recommended that LW "releave the radius in the chamber." Which they did, and now I can chamber old Hornady, old LBC, and new Hornady.

Phil

[philmurphy]

A Few Clarifying Technical Points

Before communication deteriorates let me provide some history, collected over the past year.

Lothar Walther’s 6.5G reamers are the same reamers that they made the AA barrels with, both .295 and .300 neck chambers. I believe that JGS makes the reamers. The reamers match the print.

The current AA chamber is what it is. LW does not use non-standard go-gauges, or gauges which are not based on the system specific go-gauge. LW’s gauges and reamers are all referenced to system prints.

LW is a barrelmaker that serves licensees of Alexander Arms. Their reamers have been marked 6.5 Grendel since day one. LW’s tooling is the only set of tooling that correctly matches the prints from Alexander Arms that specify an original go gauge of 1.2201".

Lothar Walther produced the Grendel for Alexander Arms, helped debug the cartridge and establish other parameters for it.

Production ammo has to be under the go-gauge dimension. It cannot be over. This is what allows for ammo to interchange in all chambers. The go-gauge is 1.2201" so the ammo must be slightly under min. The usual standard for accuracy is .0005 under min.

Ergo, if a reamer is used and the early Hornady ammo fits easily, then there is an issue with the headspace. Even with the 0.300" neck diameter, the chamber will be deep by 0.006" to 0.011".

Phil

[noone]

Philmurphy,

We are not measuring the cases at the case/shoulder radius. We are measuring at a point clearly above the shoulder radius, but somewhere from half to two thirds of the way toward the case shoulder. The case/shoulder radius is clearly visible underneath the area where we are measuring. And a feeler gauge takes a sharp drop from the shoulder up to where we are measuring the cases. Certainly, the tool Infidel470 and I are using may be a bit above or below the perfect centerline of the shoulder. The point I was trying to make is that regardless of whether I am measuring at the precise center of the shoulder, a bit above, or a bit below that line, the cases fired in the LW rifles are .007 shorter than those fired in either the AA or Sabre defense barrels. Hence our belief that the LW chambers are .007 shorter. Even if we moved to the precise centerline of the shoulder, the cases would still have a .007 variance. But that variance would be a bit longer in overall measurement to the same amount that we moved the measurement device to a point further forward.

If there is another consideration we are missing, I certainly appreciate your input. I'm not so arrogant as to believe that I know all there is about firearms, chamber measurement and so on. It just seemed like common sense to me, but of course, there is always room to learn.

[infidel470]

264 LBC/AR finish reamer was ordered! Should be here within a week ! Whoopee

[philmurphy]

Philmurphy,

We are not measuring the cases at the case/shoulder radius. We are measuring at a point clearly above the shoulder radius, but somewhere from half to two thirds of the way toward the case shoulder. The case/shoulder radius is clearly visible underneath the area where we are measuring. And a feeler gauge takes a sharp drop from the shoulder up to where we are measuring the cases. Certainly, the tool Infidel470 and I are using may be a bit above or below the perfect centerline of the shoulder. The point I was trying to make is that regardless of whether I am measuring at the precise center of the shoulder, a bit above, or a bit below that line, the cases fired in the LW rifles are .007 shorter than those fired in either the AA or Sabre defense barrels. Hence our belief that the LW chambers are .007 shorter. Even if we moved to the precise centerline of the shoulder, the cases would still have a .007 variance. But that variance would be a bit longer in overall measurement to the same amount that we moved the measurement device to a point further forward.

If there is another consideration we are missing, I certainly appreciate your input. I'm not so arrogant as to believe that I know all there is about firearms, chamber measurement and so on. It just seemed like common sense to me, but of course, there is always room to learn.

Noone,

This gauge will measure headspace at the datum. http://www.larrywillis.com/. I recommend that you get a set of certified go & no-go gauges. There are two parts to this equation: the chamber spec, and the cartridge spec.

The problem that I have written about(incorrect neck to shoulder radius of the cartridge) will negate datum headspace measurements, by pushing the shoulder backward in the chamber.

I was not measuring headspace from the neck to shoulder radius. I was measuring headspace from the datum(midpoint of the shoulder as defined by drawing headspace, 1.2201 - 1.2251.)

The solution to the equation is a 4 step process:
Get the chamber into spec (AA has available drawings),
Get the cartridge into spec (I'm not aware of an AA cartridge spec),
Try the spec cartridge in the spec chamber,
Adjust the chamber or cartridge, as required.

You may want to speak with your barrel maker, prior to altering the chamber.

Phil

[noone]

Phil,

Thanks for the response. I appreciate your knowledge. We are trying to solve this issue without a great outlay in machine parts, tools, cartridge drawings, gauges, and other things that will cost a great deal, and probably only be used once.

We also want to avoid the wasted time of arguing with barrel makers over who is right and who is wrong. In the end, that will probably end in a draw, with both makers insuring me that the other barrel maker is the one in the wrong. That would leave us back where we started in conclusions, but out the cost of shipping barrels back to the makers, having to disassemble rifles, reassemble and rezero them, and the lost time. That leaves us where we are now.

I'm using the AA chamber as the one that will not be altered. The Lothar Walther barrels on both rifles are the ones that are each .007 shorter than the AA chamber, and the Sabre defense chamber. We use fired cartridge cases from each rifle, and take an average of about ten cases from each chamber to arrive at our conclusion that the LW chambers are both .007 shorter than the AA chambers. We are not going to make the AA chambers longer. Rather, our intention is to increase both of the LW chambers to match up with the AA chambers which are longer by .007. We are using the AA chambers as the spec chambers because both of the longer chambers are AA chambers. And of course, chambers can't be made smaller. So, the only possible solutions are:
1. Make the LW chambers longer
2. live with the dramatically shortened brass life (not an acceptable option)
3. get into a fruitless "discussion" with Woody about LW barrels having shorter chambers.

If you have spoken with Woody at Lothar Walther, you are likely aware that any possible question about quality control rather quickly deteriorates into Woody is right, anyone who disagrees is wrong. Frankly, getting into that just isn't worth my time.

I would be much more comfortable discussing the possibility of over or undersized chambers with Bill Alexander. But as two of us have rifles with the same size AA chambers, are using the AA chambers as "spec", and both chambers that are .007 shorter are from Lothar Walther, it just makes more sense to have the LW chambers opened up by .007.

That just seemed like the most common sense way to go. I really appreciate your taking the time to respond, as it does give us more things to consider. With everything we have considered so far, we have both still come to the conclusion that the most common sense and cost effective thing to do is to open up the shorter chambers by .007 thou.

This option would leave us with four rifles all having the same length chambers based on the Alexander Arms chambers we currently have. It would also be the lowest cost outlay in parts as we wouldn't have to buy more spec parts, drawings, chamber gauges, measuring tools and so on.

[philmurphy]

Phil,

That just seemed like the most common sense way to go. I really appreciate your taking the time to respond, as it does give us more things to consider. With everything we have considered so far, we have both still come to the conclusion that the most common sense and cost effective thing to do is to open up the shorter chambers by .007 thou.

This option would leave us with four rifles all having the same length chambers based on the Alexander Arms chambers we currently have. It would also be the lowest cost outlay in parts as we wouldn't have to buy more spec parts, drawings, chamber gauges, measuring tools and so on.

Noone

I understand your approach. Your assumption is that the AA licensed and chambered barrels are chambered to the published AA spec. You are also assuming that an AA cartridge spec exists and that it conforms to the AA chamber spec. When and/if SAAMI certifies 6.5G, both specs will be published in the common domain. Theoretically, SAAMI members will be abe to make brass and ammo that fits the certified drawings. What will happen to rifles chambered for 6.5G, but not conforming to the yet to be published SAAMI spec? Handloaders can make adjustments. But, what about shooters that buy off the shelf 6.5G produced by a SAAMI member?

Phil

[infidel470]

Phil,
Lets assume you got 2 ar15: No. 1 has a Sabre defence bbl, No.2 has LW bbl. You got 1000 pcs of brass. Brass fired in No. 1 is .007 longer than brass fired in No.2

My solutions: dedicate 500pcs of brass to each rifle, load up all the brass to shorter chamber and fire away, get a 264 LBC/AR finish reamer and ream the shorter chamber to same dept as No.1.

Your solution: Ask BA from AA, Woody from LW, CSS, Hornady representative and SAAMI officials to present to me an approved chamber drawing of 6.5 Grendel, so I can go back to the OEM and demand corrective action for my bbls.
My choice would be the pat of less resistance and maximum benefit so I can develop one identical load and fully use both firearms. And if in a mean time SAAMI approves or disapproves the 6.5G I will deal with the forthcoming complications accordingly.
Noone was looking for an input from members on the subject of using a finish reamer in an amateur gunsmith hands. At this time a decision was made, reamer was purchased and chambers will uniformed to minimise brass overworking. We will detail the project with pictures and test data from the range.

Vasko.

[philmurphy]

Phil,
Lets assume you got 2 ar15: No. 1 has a Sabre defence bbl, No.2 has LW bbl. You got 1000 pcs of brass. Brass fired in No. 1 is .007 longer than brass fired in No.2

My solutions: dedicate 500pcs of brass to each rifle, load up all the brass to shorter chamber and fire away, get a 264 LBC/AR finish reamer and ream the shorter chamber to same dept as No.1.

Your solution: Ask BA from AA, Woody from LW, CSS, Hornady representative and SAAMI officials to present to me an approved chamber drawing of 6.5 Grendel, so I can go back to the OEM and demand corrective action for my bbls.
My choice would be the pat of less resistance and maximum benefit so I can develop one identical load and fully use both firearms. And if in a mean time SAAMI approves or disapproves the 6.5G I will deal with the forthcoming complications accordingly.
Noone was looking for an input from members on the subject of using a finish reamer in an amateur gunsmith hands. At this time a decision was made, reamer was purchased and chambers will uniformed to minimise brass overworking. We will detail the project with pictures and test data from the range.

Vasko.

Vasko,

I agree with your study guide of my position. My position is based upon forward thinking and feedback in the form of mfg cartridge modifications and mfg barrel modifications. If you, like I, hope that SAAMI certifies the cartridge, then prudence trumps expedience.

Phil

[infidel470]

Phil,
I do hope for a certification to be as expedient as possible, but it does not effect me at the moment. By the time it`s done in reality I will have to purchase 2 new bbl.
I did learned a lot from your posts and I`m grateful for your input and the wealth of knowledge.
It amazes me how much the AR15 platform has improved in the last 10years.
Vasko.

[noone]

Phil,
Again, thanks for taking the time to respond to us. I have NEVER purchased a round of factory Grendel or similar ammo. I reload for both cost, and accuracy. I believe that it is the same for Infidel470. With that being the case, whether AA, Hornady, Les Baer, or anyone else decides to release drawings, or change their specifications of the cartridge, the four chambers that Infidel470 and I are dealing with "are what they are" regardless of what any spec, or factory cartridges show.

With that in mind, the sizes of factory ammo that other folks are bickering about does not effect or affect us. We still have to deal with the fact that both of us have one chamber each that is .007 undersized. As we can't make chambers shorter, we decided to go with lengthening the shorter chambers. What anyone does with SAAMI, or outside of SAAMI won't effect the size of the chambers I have to deal with.

I'm not presuming that the AA chambers are in spec, or out of spec...it is merely the chamber that is in the rifle I own, and that chamber is .007 longer than the chamber in the other rifle. Common sense tells me that I have to deal with the chambers that I have, regardless of whether either chamber is in or out of spec. Lengthening the shorter chamber is simply the easiest way to solve the problem of having two different sized chambers.

That being said, it sure as hell would be nice if every Grendel/264LBC,6.5CSS etc were done from the same drawing, and set to the same specs. If that were the case, We would not be in the position we are.

But I understand why one company or another may want to have a proprietary cartridge in order to insure their investment. However, all the problems that these different chamber sizes causes could easily hurt the public's desire to have anything to do with an otherwise fine cartridge...much like the issues that have beset the 6.8 SPC.

Having to deal with rifles with short chambers costs time and money, and is a nuisance I would rather not have to deal with. When I told Infidel470 about my short chamber, and found out that his was precisely the same amount shorter, we put our heads together and came up with the idea to get a reamer and open up the short chambers so they would match the longer one. That way, our brass doesn't get worked so much, and thereby wear out prematurely. At nearly $1.00 per case, overworking the brass is not something we want to do. Hence our solution.

If there is a better solution that is more cost effective, and doesn't involve me having to contact a manufacturer and argue with a them over their quality control, I'm eager to find out what that is. I just can't think of one.

[Greyfox]

Noone I have an AA Overwatch with a Lothar Walther 24" barrel. I was so pleased with it that I bought a 24" target barrel from Lothar Walther for my new match rifle build. When I received my new barrel I checked the headspace with my PTG Go Guage. The bolt would not close on the Go Guage. I was a little upset and sent the barrel back to Woody. When Woody sent the barrel back, the letter said there was nothing wrong with the chamber. His CSS chamber is set to minimum headspace and it will only chamber ammo set to factory specs. Also the throat is shorter than the AA chamber.

I have the same problem as you have and it did not make me happy ether. I bought another set of Hornady dies and had to shave off the top of the shell holder in order to size my cases to .003" smaller than a fired case. I use my Forester dies for my 6.5 Grendel and Hornady dies for my 6.5 CSS. Lapua and AA brass are both too expensive to waste from excessive streaching. There is a big difference in those two chambers with fired cases.The only factory ammo I had was Wolf Gold. It would easily chamber in the 6.5 CSS so that was good.

You can not reason with Woody so do not wast your time. We went round and round about his tight chamber set to zerro headspace. I understand how you feel about this big difference in chambers . I too wanted ammo to work in both rifles.The good news is that his barrel really shoots. I use two different loads also. My AA load is AA/Lapua brass,BL-C 2 powder,120gr Sierra Match King, CCI 450 mag primer. My CSS load is AA/Lapua brass, IMR 8208 powder,107 gr Sierra Match King,Remington 7 1/2 primer. Both loads are excellent 600 yard match loads.

Hopefully this will be of some help to you on your decession.
Greyfox

[KillerMedic]

noone and infidel470,

Did you get to use the reamer? Any results to post? I have the same problem. I picked up a 22" CSS barrel and it is about .005 shorter headspace than my AA 14.5 Tactical. The bolt will not close on a PTG 6.5 Grendel GO gauge. Also the throat is way short. My AMAXes sit .015 off the lands and COL is 2.168. I would like to hear your results as I was planning on doing something similar. I really want to lengthen the throat for longer bullets and less lost case capacity with them (single fed for F-Class matches).

Medic...out!