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

[waveslayer]

You know im in WB per PM. Can anyone cofirm that the Liberty/Stoner barrels have the compound throat for sure?

the Liberty does, I have one and had it scraped. There has been a lot of chatter on here about it.

[mccuistion]

Count me in, just tell me the damage and who to send my portion to.

The borescope that Mark did confirmed that the Liberty barrels do have a compound throat... a rough one but it's there.

If you're getting a JGS reamer dulled from the neck back won't that allow for quite a bit of slop in the indexing? Seems like dull blades might not center the cutting portion in the throat as well? I'm not claiming this, just asking, as I have no idea.

[JASmith]

C...The borescope that Mark did confirmed that the Liberty barrels do have a compound throat...

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.

[WildBill3/75]

Count me in, just tell me the damage and who to send my portion to.

The borescope that Mark did confirmed that the Liberty barrels do have a compound throat... a rough one but it's there.

If you're getting a JGS reamer dulled from the neck back won't that allow for quite a bit of slop in the indexing? Seems like dull blades might not center the cutting portion in the throat as well? I'm not claiming this, just asking, as I have no idea.

The reamer I am having made is being made to the exact dimensions of the 6.5 Grendel SAAMI chamber. My understanding having talked to several reamer makers is that they believe there should be 0 issues using this style of reamer to extend the throat without changing headspace and maintaining the compound throat....even done at home with a t-handle and high sulfer cutting oil since the chamber already exists. So no I don't believe there should be any indexing issues with the reamer having a body to shoulder that doesn't cut. This reamer is made by JGS, who is one of the top quality reamer makers and I trust they will make it to the high standard they are well know for.

Right now the projected date to receive the reamer is in early June.

I'm thinking that right now just taking a headcount of all those that want in is best so I can decide the best course of action as for how to split the charges goes. I will also be the guinea pig to test the reamer before sending it to others to use.

Send me a PM titled something about the reamer so I can easily track who wants in on using it.
Thanks

[Lead Chucker]

Hey everyone needs a good reaming from time to time!!

[45r]

When I talked to someone at Dave Mansons shop I asked if dulling the reamer would work and he said a regular reamer would be better if done carefully.
I would think you could blue the shoulder area of the chamber and go slow with light pressure turning the reamer till you feel it start into the shoulder or see any blue getting scraped off the shoulder.
The barrels are soft steel and it should cut easily.
If somebody doesn't want to try it themselves it might be better to find someone who has the feel for doing it by hand.
It shouldn't cost much since it would only take a few minutes for somebody with the skill.
When I bought my manson reamer I resold it for more than half what I paid after I got done with it.

[Tedward]

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.

Are you referring to the castings of a Precision Firearms and Liberty chambers that had the Liberty Casting that was full of air bubbles? The Liberty Casting was just poor and looked like clay in a 3rd grade class project? I have no idea how you could see the results of "No Compound Throat". I could clearly see the lands were closer to the chamber resulting in less o-give but that is about the only visual difference.

[NugginFutz]

ETA: just noticed Ted has been banned. Not fair to pose a question to the recently departed...

[babaganoush]

Some people never learn to shut up. Others just never learn. Period.

[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.