Liberty barrel evaluation and repair by Precision Firearms

[Walter]

I took my Liberty barrel to Mark today to get his evaluation of the chamber and the throat. He used go/nogo gages and the chamber was fine. Next he used a bore scope to look at the chamber and throat. He said the throat was short. He all so said that the throat was not cut sqare. He did say it was the compound Gredel throat. We then put some rounds into the chamder. He drop them in the barrel and used a bolt to push them. He expected that they would drop out. They did not. This was true for 3 types of ammo he had on hand. From what he saw said there could be problems with pressure and bolts.

We talked about what could be done to fix this problem. The only solution was to put the barrel in the lathe and cut the throat with his reamer. He does each one by hand. He said that his reamer would take some of the tool marks out of the chamber and cut them square. The barrel would have a Grendel chamber, not a grendel ii or what ever. He said he would charge 75.00$ plus return shipping for Forum members if any wanted him to do there's. He would wait till he got 8 or 10 and do them all at once. This would not be a high priority for him so you may not get your barrel back for a few weeks. He said his reamer was made from the prints AA used for there reamer.

He then showed me some the barrels he was working on. Talk about works of art. He does each one by hand. That is why he can tak about .2 or .3 MOA. They cost a bit more, but man they are nice. I wish I was not so poor.

[explorecaves]

And this is why PF has gone to the top of my list of vendors to deal with.

[SHORT-N-SASSY]

Walter,

Thank you for your Report. What a breath of fresh air --- I needed that!

[BjornF16]

$75 is a bargain.

After this and Bwaites review, they will get my business. Hats off to Mark...

[NugginFutz]

It is so completely amazing what we can learn when a qualified individual has the time to actually evaluate an issue, without the all hyperbole and distraction.

Thanks, Walter, for getting your barrel into the hands of a trusted gunsmith, and relating his findings.

SNS - I agree, completely. What a breath of fresh air, indeed.

[BjornF16]

I'd still like to see a before and after casting...I'd pony some $$$ for the cause.

[jfornelli]

I'm in.

[55Kingpin]

Wow, what a coincidence. I was going to call Mark today myself to see if this is a service he would be willing to offer.

I've got three barrels to send him.

Thanks for the heads up!

[Soyben]

I talked to a local custom rifle shop about checking my barrel as well and any possible fix. He quoted me the same process and a simular price, although he said he would have to check to see if he had the specific reamer.

[Walter]

Bjorn. Mark was sure that the throat was short. Mark has alot to do and I do think he would put the time in to document the problem. He did ask me " if I thought Steve Saturn did not know the chamber is short". There is no reason to do the casting, they are short. I think everyone knows that.

Soyben. Marks reamer is made off the AA print. I think the liberty barrel reamer is made wrong. I would go with Mark and be sure your barrel is fixed correctly. After talking with him I am sure mine will be fixed correctly.

[PigOPs]

Y'all are silly. I would just load LONG and HOT and fire-lap those puppies. (THIS IS SARCASM>>>DO NOT REAM ME A NEW ONE)

[keystone183]

Y'all are silly. I would just load LONG and HOT and fire-lap those puppies. (THIS IS SARCASM>>>DO NOT REAM ME A NEW ONE)

Yes, yes, just "break them in"...

[Trock03]

Love the load long and hot comment!! I'm sure this is killing XCR. Kept wanting to explain to him that I can make a square peg fit into a round hole if I use a big enough hammer but that it doesn't make it right. I think his intentions were good but he just couldn't grasp the principal of the matter.

Props to Precision Firearms for helping with this issue. Clicking over to their website right now give them some money!

[BjornF16]

Bjorn. Mark was sure that the throat was short. Mark has alot to do and I do think he would put the time in to document the problem. He did ask me " if I thought Steve Saturn did not know the chamber is short". There is no reason to do the casting, they are short. I think everyone knows that.

Soyben. Marks reamer is made off the AA print. I think the liberty barrel reamer is made wrong. I would go with Mark and be sure your barrel is fixed correctly. After talking with him I am sure mine will be fixed correctly.

My thought wasn't just to "prove" the chamber is short, but to document the fact. In the future, there will end up being a "he said/she said" over this instead of proof certain that Satern's Liberty PTG reamer needs to be replaced with a correct reamer.

[bwaites]

My thought wasn't just to "prove" the chamber is short, but to document the fact. In the future, there will end up being a "he said/she said" over this instead of proof certain that Satern's Liberty PTG reamer needs to be replaced with a correct reamer.

Exactly the right idea. Bill A. pointed out somewhere along the line that using standard chamber casting material might not work because the material tends to shift slightly, and the measurements are so small to start with. He outlined a way to do it, but I can't find the post right now.

[Walter]

Bjorn I think we all know that the chamber is short. No matter what we do there will be a he said/she said. Saturn will do what they want any way. Unless this is going to court and a judge tells us what will happen, this is just a mess. Saturn must know they are short, or they should not make barrels. They do not want to pay for a recall, therefore no matter what is done there barrels must be in spec. Just ask Satern they will tell you, ohhhh bwaites did that. (what was I thinking) I am sure they can measure there cut barrels and see there is a difference to the liberty barrels.(I hope)

[Sputnik]

I just received my scraped Liberty 16 " barrel back from Satern. The Factory 123 Amax and Factory 123 SST fall in and out smoothly. By manually inserting the bolt and engaging the lugs and twisting to disengage, the cartridges come out smoothly and without the 5 land marks they had before. From that standpoint; all is good. What did they do? By looking into the chamber, it appears they scraped/removed all or part of the compound throat as I see a small "ring" around the throat just before the lands begin; where it looks like it was removed or slightly "bored out". I also suspect the lands were ground/scraped back a bit as well since they no longer touch the projectile. My Satern paraphrase: "They still call it a Grendel, but will allow many more lengths, sizes and projectiles with different ogives". What are the thoughts out there? Will I loose a bit of MV without the compound throat? If that's all, then I'm happy as long as it doesn't effect accuracy too too bad. This won't be free floating, so extreme accuracy will be achieved by my other rifle; my PF Neptune V.

[JASmith]

Sputnik,

From all that has been said, it appears that your velocities and especially your pressures will most likely be in line with the norms expected of factory ammunition.

The ring you observed is troubling in that there is no feature described in the SAAMI drawing that would evoke a feature like that. Furthermore, I am told that the way to fix a tight chamber is to run a finishing reamer through it. That operation should not produce the ring you describe.

Regarding accuracy, you probably will find acceptable woodland hunting accuracy with some bullets. Chances are the rifle will like one or two a lot more than others.

We know from Chapter 8 of Volume 1 of the Grendel Reloading handbook that the compound throat was developed to accommodate a variety of bullet styles while maintaining good accuracy in an AR.

We also know from both public and private statements that several, more conventional, throat designs were tried during the early development. Some of these provided excellent accuracy with some bullets, but not so good accuracy with others. Some of these earlier designs look a lot like the "alternative" chambers floated by others, including the chamber suggested as being the one Satern is now advocating and selling.

Bottom line, e caveat emptor.

Compare your scraped Satern throat with the one in your PF Neptune V. They should look alike. If not, at least one of them is not a Grendel chamber. What you conclude is worth bothering with is up to you, but folks need to know who produces barrels that meet the standards and who does not.

[Sputnik]

Thanks JASmith. I totally agree and will stick with Mark and Precision Firearms. The ring raised my eyebrows too. Mark's Maxim bolts look awesome! The bolt I got with this Liberty was a Maxim bolt that Satern got from Maxim directly. It had an extractor issue that Satern saw fit to swap out with their exclusive bolt supplier, which is Underground Tactical. That bolt was much better than the Satern Maxim bolt, but neither were as smooth as the PF Maxim bolts.

As far as the scraped barrel, I feel much better about the safety and stress factors. I will continue to wait for parts. Mark's LDM 6.5 PF muzzle brake and his PF gas block look like they will be available in about two weeks.

[hidesert cowboy]

so are these barrels indeed different than the liberty barrels that everyone used in the past?? if so what changed. or is that the question no one has the answer to??