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Barrel off center??


Boot_Scraper

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So I replaced the barrel in my PA10 with a Faxon 16". Once I put it all together I noticed that the gas block was closer to the hanguard on one side than the other. The handguard I'm using is a Diamnondhead  VRS-T. I double check the port to port alignment and its good. I mic'd the barrel to hanguard at the end of the HG and it's .067" off center to the left. Not sure if this is a barrel extension, HG, or upper receiver related problem. Any suggestions?

Thanks!

 

5998397638c7e_20170819_0811501.thumb.jpg.385a24dd23f12d294ce9e3a3d892847a.jpg

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I did not measure the original barrel. GB fit is perfect. I'm leaning towards the upper receiver being the culprit. It being the lowest common denominator in this equation. The fit between the upper and lower, for example, is similar to an old worn out barn door. I'm bout to man up and go APrecsion or F-1 on this build. 

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I removed the hg to see if it was the hg giving me a false indication. I held a square against the upper and the barrel is in fact tilted towards the right. So, I removed the Faxon and re-installed the PSA 18". Guess what... It centers up perfectly. I'll be in touch with Faxon on Monday to see what they say. Kinda bummed out. 

@FaxonNathan

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  Barrel Extension loose ? You have to make sure its the Barrel or the Barrels Port hole alignment with the Extension alignment Pin  .Not only that , but you have to make absolutely sure your Gas Blocks Gas Port Is dead center with the Barrels Gas Port , the Gas Block Port should be a little larger then the Barrels Port . 

 You also have to see if the Bas Blocks Port hole is in alignment with the Gas Tube , centered . 

 How does the Gas Tube Look in the Upper Receivers Charging Handle's Channel , when assembled to the Upper Receiver , centered ?

 Use a laser or similar straight edge to see if the Gas Port on the Barrel lines up with the Alignment Pin in the Barrels Extension .

Edited by survivalshop
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Barrel ext is good.

Gas block port to port is on as well. I even removed the gb, then put an alumnum square against the upper, and used the gas port as a point of reference. The Faxon was off centered about 1/16". Using the same method the PSA was centered .

Gas tube enters the BCG tube with little to no resistance. All good

No said laser in my arsenal. 

 

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4 hours ago, Boot_Scraper said:

Barrel ext is good.

Gas block port to port is on as well. I even removed the gb, then put an alumnum square against the upper, and used the gas port as a point of reference. The Faxon was off centered about 1/16". Using the same method the PSA was centered .

Gas tube enters the BCG tube with little to no resistance. All good

No said laser in my arsenal. 

 

 Gas tube can enter the Upper Receiver , but be cocked to one side or the other , I assume you mean its aligned or centered in the CH Channel .  Possibly the Barrels Gas Port was Drilled incorrectly or the Barrel Extension moved . Did you attach a Muzzle Device ?

 

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Yep, I had a muzzle device on it and only had to go 1/8 turn past contacting the crush washer to properly index. The problem is not with the gas tube, or gas block, the Faxon barrel itself is off to one side by about 1/16". The original PSA barrel is centered perfectly in line with the upper. 

@MrPaul , I tried that too. Torqued barrel nut to 70 lb-ft, back to zero<--repeat 2X then final 70 lb-ft. Same results. 

Edited by Boot_Scraper
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39 minutes ago, Boot_Scraper said:

Yep, I had a muzzle device on it and only had to go 1/8 turn past contacting the crush washer to properly index. The problem is not with the gas tube, or gas block, the Faxon barrel itself is off to one side by about 1/16". The original PSA barrel is centered perfectly in line with the upper. 

@MrPaul , I tried that too. Torqued barrel nut to 70 lb-ft, back to zero<--repeat 2X then final 70 lb-ft. Same results. 

I've had to do it 5 or 6 times. It may not fix your problem but its worth a try. I've never monkied with faxon barrels so I don't know the suggested torque specs. Maybe its over torqued. All I can say is I've had the same issue on several occasions and it's a trulley frustrating experience but I've always been able to fix it that way. I would think its pretty hard for a barrel that's not straight to make it past even the most elementary q.c. checks. 

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10 hours ago, Boot_Scraper said:

Yep, I had a muzzle device on it and only had to go 1/8 turn past contacting the crush washer to properly index. The problem is not with the gas tube, or gas block, the Faxon barrel itself is off to one side by about 1/16". The original PSA barrel is centered perfectly in line with the upper. 

@MrPaul , I tried that too. Torqued barrel nut to 70 lb-ft, back to zero<--repeat 2X then final 70 lb-ft. Same results. 

  Do you have a Photo of the Faxon Barrel with the straight edge on it ? Also a Photo of the Upper Receiver where the Gas tube enters it .

   What are your measurement aligning points , meaning , are you using the Upper Receiver alignment Pin on the Barrel Extension & referencing the Gas Port on the Barrel ? 

  The reason I asked about the Muzzle Device is , depending on how the Barrel was secured to install it , there have been many cases of moving the Barrel with in the Barrels Extension , by not securing the Barrel with Vice Blocks.  Using a Upper Receiver Block is not the Proper tool for Muzzle device removal or install , nor is the tool to hold the Barrel Extension locking lugs . 

   The reason I ask all these question is, to make sure its the Barrel & not something else before you send in .

Edited by survivalshop
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@survivalshop I appreciate the help! Here's some pics to help convey my method of madness.

So I'm using a square flush against the side of the upper, just below the rail.

20170820_093135.thumb.jpg.464617dfb96350b0cb58e148fd32693c.jpg

 

Using the port as a reference point, I take a measurement on both sides. Here's the PSA barrel. 

 

59999ef03886a_psa(1).thumb.jpg.0aee0492e968836e8e9c29ab6bf04c5d.jpg59999ef1f01c0_psa(2).thumb.jpg.bbc8973827df4a53c0825b91d543d6b9.jpg

 

Here's what the Faxon looks like.

 

59999f3280f78_Fax(1).thumb.jpg.cc7d0a2d3a1b23299038b6991e84d18e.jpg59999f353a888_Fax(2).thumb.jpg.77e278ff93e635514605cbb7ca0aae44.jpg

 

You can see that the barrel is taking a left turn. Even when using the outside of the barrel as a reference (to dismiss a offset port location) the discrepancy is repeated. No muzzle device installed, only the barrel nut.This time I only went to 50 lb-ft to see if MrPaul might have been onto something.

 No worries though. from what I can tell, Faxon will fix me up. Nothing in life is perfect. Thanks again for the help. I'll keep ya'll posted. 

 

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Take the barrel off, roll it on a flat surface. If there is wobble in the middle. The barrel is bent. If there is no wobble roll it with the extension hanging off the edge of your flat surface while looking up the chamber. If the chamber appears to wobble your extension is not on right. If this doesn't show any wobble...its an installation issue and not the barrel.  In My experience its always been something with the installation and not the barrel.  

I've used your straight edge method before but its not conclusive because the extension nub is covered by the barrel nut and you have to see that the nub and the gas hole don't line up on the square to see that the barrel is bent. 

Just my opinion and methods...hope it helps if not I'm sure faxon will help you.

Edited by MrPaul
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18 minutes ago, MrPaul said:

Take the barrel off, roll it on a flat surface. If there is wobble in the middle. The barrel is bent. If there is no wobble roll it with the extension hanging off the edge of your flat surface while looking up the chamber. If the chamber appears to wobble your extension is not on right. If this doesn't show any wobble...its an installation issue and not the barrel.  In My experience its always been something with the installation and not the barrel.  

I've used your straight edge method before but its not conclusive because the extension nub is covered by the barrel nut and you have to see that the nub and the gas hole don't line up on the square to see that the barrel is bent. 

Just my opinion and methods...hope it helps if not I'm sure faxon will help you.

 Damn good idea! I have an arrow saw that I also use to spin test my arrows. I pulled it out and the barrel spins true but the barrel extension does wobble. You can see the step difference. 

20170820_114845.thumb.jpg.20c624122f48ac836403bd3310b51db0.jpg

High

20170820_115217.thumb.jpg.61fdb57992735e92f9bf80011208b87f.jpg

Low

20170820_114924.thumb.jpg.12baea75547ecbdd99f49a8a75f090a6.jpg

 

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  Yep , send it back , Faxon will take care of you . Thats a good idea to use your Arrow Saw :thumbup:

 

  When I hear of an issue like yours , I try to document it , so it can be used later , if needed . Nothing about the Barrel maker , just if it comes up again .

    I have a very early FF Hand Guard ( 70's ) made by Olympic Arms , its one of those early ones that are the Barrel Nut all in one , this one happens to be made of Steel & no matter how many times you mount the HG , its off when you look down the front , Barrel not centered , has to be in the Threads or the Threaded Barrel Nut was not welded correctly & is off .

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1 hour ago, Boot_Scraper said:

Thanks for the help fellas. Love this group. :hail::thumbup:

I had high hopes for Faxon after looking into their reputation. Hopefully it's an isolated incident (I'm sure it is). My luck as usual. 

You will not be disappointed 

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