SHORT THROAT OWNERS--Who's up for chipping in for a reamer to fix our issues?

[LRRPF52]

I'm still getting PM's from people who did know anything about this, and are piercing and blowing primers with Liberty barrels using factory ammunition.

That's their first welcome to the "6.5 Grendel". This is what we have tried to prevent all along.

[rickOshay]

Had a guy come up to me at the range Monday with a question about reloading his new Grendel. He was complaining that he could only get 2.2" of COAL and thought that was a big limitation for Grendels. I asked where he got his barrel, and he said "AR Stoner Midway USA". I bit my tongue and gave him a brief summary of the "Liberty Barrel Fiasco of 2014" - and he was relieved to hear the Grendel was not supposed to be that limited. I gave him a link to Precision Firearms for a remedy for this short throat.

A stroke of luck that the Range Officer he first posed the question to is also the printer for Volume 2 - and directed him my way.

[NugginFutz]

Funny how that worked out, isn't it? Pure serendipity, if you ask me. You couple your experience, along with some other recent reports, with the knowledge that MidwayUSA has discontinued the entire line of AR Stoner branded 6.5's and you just might think there really IS something to all this.

[nincomp]

WildBill and others of yall who will be using an in-spec Grendel reamer on the throats of their barrels, I wonder if you could take the time to see what section of the throat begins cutting first, and then if all of the remaining throat needs some metal removed. I think that this could be done by sight, or by coloring the edges of the reamer with dychem or a sharpie. If someone us doing this by hand, the first area to make contact might be seen more clearly by turning the reamer backwards.

I have no reason for asking this other than my own curiosity, so if it is any trouble, please do not bother. In my mad scientist mode the other day, I thought up a number of reasons why any one or all of the surfaces might not meet spec. I just wonder if any of my ideas are right or whether I missed the boat completely.

While in that mad-scientist mode (also called insomnia), I ran some quick calculations from the SAAMI drawing. Then I did a rough scaling of the photo of the chamber casts (and when I say "rough", I'm not joking). According to the SAAMI drawing, on a barrel with a bore (lands) of 0.256" diameter and grooves of 0.264" dia, the rifling should become apparent fairly near the beginning of the 0.5 degree section (the beginning of the 0.5 degree section of the throat is only 0.2644" diameter). In other words, the rifling should show up in the first section of the throat.

Using my non-calibrated eyeball, the rifling breakthrough should be somewhere between where it appears on the two chamber casts. One of the problems is that I cannot tell if there is any 0.5 section of throat or if the 1.5 degree section starts at the right place or, for that matter, is if that section is really 1.5 degrees after all.

If the transition from the neck to the throat is short, this would be interesting to know.

Is this where I should do my Mad Scientist laugh? Mwwaaa hahaha!
Thanks,
Jim

[NugginFutz]

WildBill and others of yall who will be using an in-spec Grendel reamer on the throats of their barrels, I wonder if you could take the time to see what section of the throat begins cutting first, and then if all of the remaining throat needs some metal removed. I think that this could be done by sight, or by coloring the edges of the reamer with dychem or a sharpie. If someone us doing this by hand, the first area to make contact might be seen more clearly by turning the reamer backwards.

I have no reason for asking this other than my own curiosity, so if it is any trouble, please do not bother. In my mad scientist mode the other day, I thought up a number of reasons why any one or all of the surfaces might not meet spec. I just wonder if any of my ideas are right or whether I missed the boat completely.

While in that mad-scientist mode (also called insomnia), I ran some quick calculations from the SAAMI drawing. Then I did a rough scaling of the photo of the chamber casts (and when I say "rough", I'm not joking). According to the SAAMI drawing, on a barrel with a bore (lands) of 0.256" diameter and grooves of 0.264" dia, the rifling should become apparent fairly near the beginning of the 0.5 degree section (the beginning of the 0.5 degree section of the throat is only 0.2644" diameter). In other words, the rifling should show up in the first section of the throat.

Using my non-calibrated eyeball, the rifling breakthrough should be somewhere between where it appears on the two chamber casts. One of the problems is that I cannot tell if there is any 0.5 section of throat or if the 1.5 degree section starts at the right place or, for that matter, is if that section is really 1.5 degrees after all.

If the transition from the neck to the throat is short, this would be interesting to know.

Is this where I should do my Mad Scientist laugh? Mwwaaa hahaha!
Thanks,
Jim

Jim,

No need to apologize - I was curious what a cross section of those casts would look like, if they were cut in half down the centerline. I believe they were zinc casts, but I don't actually recall that being specified. Either way, I'd like to see that for no other reason than to satisfy my curiosity, as well.

[nincomp]

Part of my curiosity stems to the unusual design of the Grendel's throat. Depending on a number of things, including how much metal is removed by the roughing reamer, a Grendel reamer may wear differently than a less complex one. It is possible to get extra life from a reamer by using carbide of one of the various coatings, but the basic wear pattern would remain the same.

I found it interesting that Winchester did not use a coating on their roughing reamers (I bought one on eBay not long after the plant closed*).


* I thought that I was buying a finish reamer. **

** I also learned that one should never go to the eBay site soon after an injury, least if you are taking muscle relaxants and prescription pain meds.***

*** It is amazing how much money you can spend quickly on neat stuff that you do not need. See ** above.

[WildBill3/75]

You do not want to turn a reamer backwards as you run a risk of dulling it.

I'll be sure to post a "how I did it" when I get this going.

Right now it just entails;
1. High sulfur cutting oil
2. Air compressor to remove cut material
3. T handle to turn reamer

I plan on turning the reamer tell it deadstops on the shoulder.

[JASmith]

Is there a possibility of starting a fresh thread with a title along the lines of: DIY Throat Adjustments and maybe put it into the Grendel Build-It-Yourself & Custom Builds forum?

That would both minimize the number of posts one has to read through to discover how to do it and create a more positive title.

(and yes, at least one of the folks doing the chore will have an Aw-Sh** moment -- it is the nature of the business!)

[mccuistion]

The sensitivity of this topic means that we have to be very careful with our statements, lest we spark another series of pointless and painful posts.

Can you expand on this statement? How many barrels were examined? What were the results?

Remember that at least one chamber cast indicated that there was no compound throat.

This statement was referring to the question of IF the liberty barrels have a compound throat. I was just stating that the borescope performed showed there was what looked like a compound throat.

I was deployed and I must have missed a thread including a chamber casting? Was it a casting after the barrel was scrapped?

[JASmith]

This statement was referring to the question of IF the liberty barrels have a compound throat. I was just stating that the borescope performed showed there was what looked like a compound throat.

I was deployed and I must have missed a thread including a chamber casting? Was it a casting after the barrel was scrapped?

Did you personally do the inspection, or did you personally talk to the person who examined the throat, or are you partly parroting third hand half-quotes?

Are you asking about "scrapped" as in tossed out, or "scraped" referring to an undefined "adjustment to a chamber"? The threads containing the casting image are still in the database and accessible. You are welcome to find them. If I recall correctly they are less than 60 days old, but may have been closed -- they are quite lengthy and repetitious.

As for the first part of the question, had one done any reasonable read-through it would be obvious that NO-ONE has claimed or hinted that ALL Liberty or AR Stoner barrels are or were out of spec. What is true is that the symptoms suggest that a significant number came out of the shop that way.

This means that a fair fraction WILL show the compound throat, and a number won't.

Is there a reason we seem to have trouble understanding this issue and bringing it up again every two weeks or so?

[NugginFutz]

This statement was referring to the question of IF the liberty barrels have a compound throat. I was just stating that the borescope performed showed there was what looked like a compound throat.

I was deployed and I must have missed a thread including a chamber casting? Was it a casting after the barrel was scrapped?

Well, since you were deployed, there has been no shortage of static to sift through. Here is the link to the thread where the pictures of the castings are. If you can see a compound throat, please show me. I can only detect a possible shadow, well into the rifling, at the roughly the location where the PF barrel's compound throat is clearly visible. It is an unfired, unscraped chamber.

http://www.65grendel.com/forum/showthrea...#post90748

(Search is your friend)

[mccuistion]

Did you personally do the inspection, or did you personally talk to the person who examined the throat, or are you partly parroting third hand half-quotes?

Are you asking about "scrapped" as in tossed out, or "scraped" referring to an undefined "adjustment to a chamber"? The threads containing the casting image are still in the database and accessible. You are welcome to find them. If I recall correctly they are less than 60 days old, but may have been closed -- they are quite lengthy and repetitious.

If looking at a borescope picture of a throat with a caption that says "this is the liberty compound throat" is parroting third hand half-quotes then yes. Come to think of it... expressing the findings of the chamber casting would be parroting half-quotes also then, right? both instances examined one barrel and got conflicting results. "Scrapped" was a mistype, I was trying to ask if the cast was performed after Saturns "fix" was implemented because I would like to see a cast of that also.

I don't appreciate your hostility. However, I understand why there is this attitude towards any conversation regarding these barrels after the last several months events. At this point there is no dead horse left to continue beating.

As for the first part of the question, had one done any reasonable read-through it would be obvious that NO-ONE has claimed or hinted that ALL Liberty or AR Stoner barrels are or were out of spec. What is true is that the symptoms suggest that a significant number came out of the shop that way.

This means that a fair fraction WILL show the compound throat, and a number won't.

Is there a reason we seem to have trouble understanding this issue and bringing it up again every two weeks or so?

I have no idea what this comment is in response to... I didn't bring any of that up and don't intend on arguing with you over it, too many useless posts have already been devoted to the subject. The question was asked if the barrels have compound throats and I answered based on my experience and the barrel I received.

If I was asked the same question again, even after seeing the chamber castings, I would answer it the same way. If a company makes a barrel with the intention of giving it a compound throat, then those barrels have a compound throat; If a reamer gets dull and doesn't properly cut the throat that is a factory defect.

Maybe I misunderstood him, either way i'm over it and would like to focus on fixing my barrel not nit-picking other contributors.

[BluntForceTrauma]

WildBill updated his original post that he ordered a reamer. Those who want to work with him on it, please contact him privately. If there are no more comments on the original post, I'll close this thread.

John