head space? gas ring?

[pokey]

 I've read that head space in an ar10 is larger than that of a bolt action rifle,  is this true?  Would it be typical for a ar10 to close on a NoGo, be it barely (using the force of one finger).  Would anyone happen to have the bolt dimensions between the ar10 and the dpms pattern bolts.  Just the bolts, not the carriers. 

  Also, is it typical for the gas rings to be weak enough that while holding the bolt carrier bolt up, the bolt won't stay up (the weight of the bolt only, not the carrier). In ar15's I know you can hold the bolt facing down and the carrier won't drop.

   Thank you

    POKEY

[jtallen83]

The bolt should not close on a no go gauge. Chamber specs are the same regardless of action type.

If my bolt slid down from nothing more than its own weight I would change the rings.

Edited January 8, 2017 by jtallen83

[pokey]

I've seen where on ar15's they will also use a field gage, I assume is larger. I don't know when this would be appropriate.

[jtallen83]

Here is a detailed explanation;

http://www.brownells.com/.aspx/lid=12555/GunTechdetail/Headspace-Gauges-And-How-To-Use-Them-Part-I

[survivalshop]

 What is your Chamber ?  7.62 x 51 Nato or .308 ?  What Head Space Gages are you using .  You could have bad Gages also .

[pokey]

What ever chamber a Armalite has. The NoGo gage is a Clymer 308 WIN 1.634.

[survivalshop]

 The Armalite people here can answer better , but I think they are all Nato chambers ,  I'm not the one to make that as fact for sure though .

[pokey]

The rifle was a stripped receiver build by someone else. There are no visible markings on the barrel. Everything appears to be Armalite.

[pokey]

 I now understand Go - NoGo - and Field gages (after a lot of reading)  Now I see there are Nato head space gages as well. The Armalite, on there site looking at new barrels have a 7.65 X 51  / .308 chamber, which I think means it's a Nato chambers.

[survivalshop]

19 hours ago, pokey said:

The rifle was a stripped receiver build by someone else. There are no visible markings on the barrel. Everything appears to be Armalite.

No markings on the Barrel ? That's strange .

 By holding the BCG upside down with the Bolt in Battery position when flipping it upside down , it should not drop to to fully extended position . Bad rings , out of spec , BC or Bolt  or worn out components.

[pokey]

I should mention there is a free float tube that may hide any markings.

[survivalshop]

1 hour ago, pokey said:

I should mention there is a free float tube that may hide any markings.

It may be to your advantage to remove the HG to see the markings on the Barrel . They are normally at the end of the BBL. , but that is not followed by all BBL. manufacturers. 

.

 

Edited January 9, 2017 by survivalshop

[shepp]

1 hour ago, survivalshop said:

It may be to your advantage to remove the HG to see the markings on the Barrel . They are normally at the end of the BBL. , but that is not followed by all BBL. manufacturers. 

.

 

MIGHT BE, lol