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head space problems


hired_gun

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I am building 2 .308 rifles and have run into the same problem with both

 

Neither one will pass a headspace test.  The bolt won't close on a "go" gage, or a "no go" gage or even a dummy 308 round.  It stays open and comes nowhere near being closed.

 

I tried swapping bolts between rifles, no difference

I tried a third bolt I had on hand, same thing

I tried it with the extractor in as well as out, still nothing.

 

They will fully close without anything in the chamber, but not with the dummy round or headspace gages.

 

one rife is a DPMS carbine style barrel with a DPMS bolt and DPMS upper

The other is an Ares Armor barrel with a DPMS upper and an Ares Armor bolt.

 

Any suggestions or help here would be appreciated.

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 Are the manufacturers of the Barrel the same ?

Are the BCG's/Bolt  made by the Same Manufacturer ?

 

 Check the Function of the Ejector , which depending on what HS gages you are using , should be removed for testing , the extractor can stay on most, if not all HS gages.

 

 What kind of Dummy round , hand load or a factory made one ?

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Hired   How are the cams acting..do they rotate when the bolt is pushed in and pulled out?  Did you  service the bcg ? Are you using the charging handle and letting it slam forward without anything in chamber? did you take the upper with it facing down and drop the bcg into the upper...it should almost go into battery..and a lil slap with palm will finish it off? did you grease up the lugs just a lil? is your gas key and even your charging handle freely going onto the gas tube? Is your barrel index pin seated all the way in the upper? Is the nitride wearing off on the bolt lugs in certain places? have you put a live round in a mag and let the charge handle go?  :) Wash

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Hired   How are the cams acting..do they rotate when the bolt is pushed in and pulled out?  Did you  service the bcg ? Are you using the charging handle and letting it slam forward without anything in chamber? did you take the upper with it facing down and drop the bcg into the upper...it should almost go into battery..and a lil slap with palm will finish it off? did you grease up the lugs just a lil? is your gas key and even your charging handle freely going onto the gas tube? Is your barrel index pin seated all the way in the upper? Is the nitride wearing off on the bolt lugs in certain places? have you put a live round in a mag and let the charge handle go?  :) Wash

 

He did that already, brother. See below.

 

They will fully close without anything in the chamber, but not with the dummy round or headspace gages.

 

I'm with Mack on this - different caliber might have something to do with it.  More detail on the barrels is necessary here.  Like, post direct links to the barrels purchased, from the dealers websites - not pics of the barrels.  Manufacturers links, when I would go to add them to my cart...

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  Are the Bolts NIB coated ? They can be tight .  I do all head spacing testing with dry Bolts & Barrel Extensions 

  

 

  I could see one being the wrong marked caliber , but two different barrels from different manufacturers ?

Survival is on the money!  strip down both units and head space with barrel and bolt...the only true way to find your problemo.

you can have the carrier and even the charge handle give you bad readings....ive seen it      :) Wash

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all BCG are lubed.

 

When the chamber is empty they close and function perfect.  As long as nothing is inthe chamber the bolts/cam will rotate and lock fine.  The problem it the moment the gages or dummy is put in then they wont rotatate and close at all.

 

Gas key and handles appear to be going in fine.  I even tried swapping the charging handles and still had the problem.  With the gages in the handles will close all the way and lock but the bolts wont budge.  I believe if I really tried to put the pressure on them Could maybe force them to close but that aint right

 

For the record the gages are Forester and the dummy is a factory round I dumped the power out of and pulled the primer.

 

I am going to try removing the ejectors to see how that works.  I know it has to be me on my end so I will go thru the whole thing from step one

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Coating on the bolt face is adding a thousand or two. This happened with a few manufacturers with anodized parts not fitting takedown and pivot pins in holes.

Exactly...thats why I asked him to look at the lugs for the coating wearing.... he could have a coating or whatever on both the bolt and the extension..  :) Wash

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Exactly...thats why I asked him to look at the lugs for the coating wearing.... he could have a coating or whatever on both the bolt and the extension..  :) Wash

Now we need SS to say the same thing since he was leading with his last question.
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the Ares barrel is stainless and the bolt is nickel boron

 

I also originally tried the headspace with just the bolt and barrel before I assembled them and had problems.  I wrote that off to the ejectors as they seem so damn tight and strong.

 

I also did "slam" the bolt on a dummy round and played hell trying to pull the bolt back.  Its like it just wasnt coming back.  When it finally did release the bolt, with the extractor removed, they round was so jammed in I had to force it out with a cleaning rod

Edited by hired_gun
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Wash, I am going to try it from a magazine feed.  Previousy I dropped the round in by hand and let the bolt go on it.  Plus this is a better dummy then the last so we will see what happens

Hired   Well crap.... do that and let the handle fly... ill tell ya right now... you will have trouble removing the round from the chamber..as its tight and new...dont whack on the charging handle either. when trying to get the round out 

I think what you need is my old standby plan B... you take your rifle to the local range...and I know there's gotta be a know it all A-hole range officer. Unpack your rifle load up the mag,and then go over to the range officer and tell him you dont know $hit about this rifle and would he shoot it for you....there ya go  easy peasy    oh...stand behind him   :) Wash

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Hired   Well crap.... do that and let the handle fly... ill tell ya right now... you will have trouble removing the round from the chamber..as its tight and new...dont whack on the charging handle either. when trying to get the round out 

I think what you need is my old standby plan B... you take your rifle to the local range...and I know there's gotta be a know it all A-hole range officer. Unpack your rifle load up the mag,and then go over to the range officer and tell him you dont know $hit about this rifle and would he shoot it for you....there ya go  easy peasy    oh...stand behind him   :) Wash

I like that idea.
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