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Powerman

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FA rifle length gas system will use a std AR 15 rifle length gas tube . I have two & they work fine ( 16"& 20" ) I have never heard of a FA ,Kreiger Criterion barrel, having a bad chamber ,but they are mass produced & any thing is possible .

 

I thought at first , looking at your spent failed brass, That they were ejecting prematurely & may be , but the barrel extension ,locking lug marks are probably from the BCG force ing the spent case against them.

 

I have a CMMG lowered build , that will not function reliably with PMags , you need to find another manufacturers mag that is known to work in another like rifle to test.

 

I think its all in the bolt , your not the first to have problems ejecting with JP's bolt . They make top of the line parts & rifles , but as with anything else , any manufacturer can have a bad production run , I don't care what name brand they are under .

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If for some reason the mags turned out to be the problem you will have no problem getting your money back take some good calipers and measure the gas block from the rear end to the center of the hole then measure the barrel from the center of the hole to the same measurement as the gas block that should give you center of hole and how much to have it off the shoulder..... and i agree that the brass does not look good it is getting fooked up somewhere in the chamber.

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Deburr what would be the rearward edge of the relief cut in the extractor it looks like this is hitting the back of the case, I had the same problem with one, I used a dremel with a cutoff wheel to remove a little from the rear of the cut,  this also makes the rough chamber problem worse by driving the case into the chamber, do you have access to a lathe?

Edited by texas30cal
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Power  you dont have to measure the gb...break open the rifle or just remove the upper....if you have a muzzle break wrap some tape around the openings put mouth to muzzle/brake...put finger into chamber....give it a blow....you should hear air rushing out of the gas tube....and hard to believe not that much resisitance....if its doing that...you are gtg.... you did drop the bcg into downward pointing upper...go into almost battery?   If its locking back like you say....you got it mostly.. could be the jp bolt..if you want hell ill send you one of my bolts?....and as Terry said i think your chamber is fubared from all that oil drenching you gave it....since the rifle is mostly working...the chamber may have crud burned in it  :)  Wash

 

You know what?  I read again where your brass is falling and how far....thats just about perfect in my book

your gas is okay I would think now that ive digested this...(belch) give it a bj for piece of mind,but I think the gb is doing its job...as for leakage new one on me?   we are down to the jp bolt and chamber

Edited by washguy
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Deburr what would be the rearward edge of the relief cut in the extractor it looks like this is hitting the back of the case, I had the same problem with one, I used a dremel with a cutoff wheel to remove a little from the rear of the cut,  this also makes the rough chamber problem worse by driving the case into the chamber, do you have access to a lathe?

 

Yes I do, but I'm no machinist.

 

I can take care of the extractor. Curious what JP is coming up with.

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Powerman   couldnt stand it..so I called Fulton for you

told him what you are going thru an this is what he said....and dont shoot the freakin messenger....lol

 

1  a standard length gas tube will work..but sometimes you need the longer one...they are not in control of the placement of hole

2 their stuff is  to work with a dpms tube buffer and spring

3 a jp bolt totally different animal from their bolt (dpms)and carrier and could be the problem

4 you have a stacking tolerance issue with the gas block and tube....gas tube hole too big for block...he's seen it before

5 you fubared your chamber with oil/grease while breaking it in...baked on stuff.....told ya...lol

6 you fubared your gas tube key with all that oil ,so take a pipe cleaner and clean out gunk!

7 headspacing is a must...he has to say that...we all know that

8 put down the finishing reamer and slowly walk away....thats for a smith

 

thats all I got from them      :)  Wash

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Powerman   couldnt stand it..so I called Fulton for you

told him what you are going thru an this is what he said....and dont shoot the freakin messenger....lol

 

1  a standard length gas tube will work..but sometimes you need the longer one...they are not in control of the placement of hole

2 their stuff is  to work with a dpms tube buffer and spring

3 a jp bolt totally different animal from their bolt (dpms)and carrier and could be the problem

4 you have a stacking tolerance issue with the gas block and tube....gas tube hole too big for block...he's seen it before

5 you fubared your chamber with oil/grease while breaking it in...baked on stuff.....told ya...lol

6 you fubared your gas tube key with all that oil ,so take a pipe cleaner and clean out gunk!

7 headspacing is a must...he has to say that...we all know that

8 put down the finishing reamer and slowly walk away....thats for a smith

 

thats all I got from them      :)  Wash

 

:)) That's awesome.

 

I was not thrilled about the reamer. I have taken pipe cleaner to tube and it's clean.

 

 I think I am just going to get a flex hone and clean it up. I am going to head space so I do not have to explain for the rest of my life that I didn't :))

 

Did he happen to say what the proper engagement is between tube and key?

DPMS buffers are lighter. But plenty also run Heavy Buffers. Not sure what it does for Fulton... other than sped things up from what I have now.

Edited by Powerman
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Powerman    dammit for got to ask him about that...sorry  :)  Wash

 

 

Did he happen to say what the proper engagement is between tube and key?

 

btw....when putting tube into gasblock....was it tight going in gb? or loose? you shouldnt have play or gasses coming out he said 

Edited by washguy
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   Sorry to be a broken tape deck.....But that frosted "belt" around the case says, to me, as a full time gunsmith, that you have a tight chamber.

    A 'smith shouldn't charge you over $20 bucks to check the headspace, unless he has a mim charge, and taking the bbl off, running a reamer in, and polishing the chamber shouldn't cost over a bill($100) for everything.

    Setting  excessive can be a real pain in the A$$..   Unless you have access to a LARGE number of bolts, and the excessive headspace is not to great.

    If your going to be in this game, as go and no-go set of gagues is a cheap investment.  Let me know, and i'll give you a run down on how to use them.

    Respectfully

     Terry

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Powerman dammit for got to ask him about that...sorry :) Wash

Did he happen to say what the proper engagement is between tube and key?

btw....when putting tube into gasblock....was it tight going in gb? or loose? you shouldnt have play or gasses coming out he said

Yep, gb is good to go easy flow.

It isn't like the tube is rattling around, but it went in surprisingly easy. Gas tubes are cheap. Even just stopping the fouling is enough reason.

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Sorry to be a broken tape deck.....But that frosted "belt" around the case says, to me, as a full time gunsmith, that you have a tight chamber.

A 'smith shouldn't charge you over $20 bucks to check the headspace, unless he has a mim charge, and taking the bbl off, running a reamer in, and polishing the chamber shouldn't cost over a bill($100) for everything.

Setting excessive can be a real pain in the A$$.. Unless you have access to a LARGE number of bolts, and the excessive headspace is not to great.

If your going to be in this game, as go and no-go set of gagues is a cheap investment. Let me know, and i'll give you a run down on how to use them.

Respectfully

Terry

Thanks... So help me out, why do I need my chamber reamed and not just cleaned/polished/honed? I'm not get why I need to remove so much material. Why not the flex hone?

I have not asked specifically, but I have a couple friends that probably have 308 gauges.

Thanks a lot.

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GS455 started a thread that has some good pics of brass from a rough chamber and I posted there about how my local smith had me polish my chamber and it works great, it ripping the rim off before, you are removing very little material, unless you get carried away we are only talking about tenths of thousandths or 4 decimal places.

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Powerman Terry has it nailed I would think :) Wash

 

Only seeking knowledge, not dismissing. Just trying to learn... and thanks for all your help. I really regret getting my panties in a bunch with you... but it was somthing with the fabric softener because all my panties were pretty bunched for a bit. It's all good now. :))

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   Typicaly, reaming will remove more metal than honing, except A LOT of honing.  And then, your honing might not be to the specs of the chamber taper, etc.

    The finish reamer specs the WHOLE chamber.  As I stated, in my paticular case, metal was removed from the entire BODY of the case, but did not touch the shoulder, neck or throat.   In another case, it MIGHT remove metal from the neck, or throat.

    Respectfully

    Terry

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If the barrel will not head space correctly , send it back, /w bolt to Fulton Armory . That way, if there is a chamber problem , they will repair or replace the barrel & all you have to do is pay for shipping & maybe for checking head spacing . That will take those two factors out of the equation.

 

FA says , they have a special chamber & a std reamer may not work or could make your problem worse.

 

 

I've been building & repairing these type rifles for over thirty years & have never came across a bad chamber , not saying its not possible , with mass production , but not a normal problem . Maybe some here are finding bad chambers ,left & right ,I just don't & if I did I would send it back to the Manufacturer, if its new.

 

One other thing , if it has a bad chamber , wouldn't you think it would have a problem ejecting almost every round fired & not just with ten in two hundred rounds fired ?

 

 

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I don't think that anyone answered your polish question earlier.  I've been researching it for a while and once my hone arrives I'm going to give it a shot.  In short, you don't want to polish.  Here are some helpful links:

 

http://thefiringline.com/forums/showthread.php?t=394688

http://www.varmintal.com/a243z.htm

 

And I ordered a 800 grit hone and oil from these guys (Brownells didn't carry one for a 308??? and Midway was out of stock): http://www.brushresearch.com/

Watch the video on their page.  Looks easy enough!

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I don't think that anyone answered your polish question earlier.  I've been researching it for a while and once my hone arrives I'm going to give it a shot.  In short, you don't want to polish.  Here are some helpful links:

 

http://thefiringline.com/forums/showthread.php?t=394688

http://www.varmintal.com/a243z.htm

 

And I ordered a 800 grit hone and oil from these guys (Brownells didn't carry one for a 308??? and Midway was out of stock): http://www.brushresearch.com/

Watch the video on their page.  Looks easy enough!

 

Thanks Bud. I have been looking at that kind of stuff. My box of AE 7.62 got here. I'm going to get my rifle put back together and cleaned up right. I will find some gauges or have it head spaced. If it isn't right, I'll send it back to Fulton. If it is, I'm going to make sure the chamber is clean with a flex hone. At least I will know it's smooth, and clean up any scratches I may have caused. After that... I'm feeling good it will be right, and the new extractor will do it's job.

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