View Full Version : Headspacing
brzusa.1911
08-27-11, 07:09
I am picking up another DD upper, I have DD lower and DD BCG to go along, should I be concerned about headspacing, send it to factory to check? I am not planing on getting the gauges.
You will be g2g for sure if you are using all DD factory parts. In fact you could even use a colt or BCM or many other manf. BCG's in your upper and the headspacing would be acceptable, does that mean it would be proper in every instance and you shouldn't gauge it? No but as it is you have a bolt and barrel by the same proprieter and they will mate nicely.
A simple search would have revealed plenty of previous discussions about headspace.
Although I always check the headspace it is generally assumed that if you are using quality known manufactured components (which you are) then you are probably safe.
But, if you buy a simple "Field" gage then you have extra insurance.
brzusa.1911
08-27-11, 16:11
I wasn't planning on getting a gauge, but I think I will. Can you recommend one? All I found were go no-go ones which require to disassemble the bolt, do all gauges require to disassemble the bolt?
Numrich (http://www.e-gunparts.com/) has Forster (http://www.forsterproducts.com) brand gauges that are grooved and drilled for use w/o stripping the bolt and the Clymer brand that Brownells offers also appear to be simularly machined.
Last I looked Numrich only had go and no go, but no field.
Dunno about Brownell because I wanted Forster gauges anyway.
from the pictures on the Forster web site, their guages are not cut outr so you have to strip the bolt. Who makes a mil-spec guage that doesn't require stripping the bolt. I know there is one, just can't remember.
You're saying these pix directly from the Forster site don't look like the gauges are cut out and the bolt must be stripped to use them?
Go, 5.56mm NATO
http://www.forsterproducts.com/product_images/catalog19938/NATOChmbrHeadspceGageWL.jpg
No-go, 5.56mm NATO
http://www.forsterproducts.com/product_images/catalog19938/NATOChmbrHeadspceGageWL.jpg
You absolutely sure about that?
I mean mine look just like that and work perfectly without having to strip the bolt.
They even extract and eject upon retracting the BCG.
I can't tell for sure. But, if you compare it to a military gage they are different. The military gage has a more rebated or recessed rim. In fact it only touches the bolt face and not the extractor or ejector.
Bushamster does does a "field" headspace gage, but it still has the non-MIL type of rim.
I know of the ones you speak.
They are turned down, well ground actually, on the end so that there's a round protrusion that is of smaller diameter than what the extractor and ejector pin represent on the bolt face. It just barely covers what area the 'primer circle' ends up on on the face.
Put them in, run the bolt forward, dump them out manually or suck them out with a stick magnet.
The Forsters are grooved with an extractor ridge and have a recess hole drilled in them to clear any potential firing pin protrusion, *which isn't present for whatever reason on the above described IIRC.
The only instance of bolt stripping that Forster mentions in any of thier instructions is in regard to bolt actions.
It is suggested that the extractor be removed from them to help get a better feel and free-er bolt rotation as the lever arm that the bolt handle represents can do a pretty good job of messing something up if worked too hard due to a numb feel.
There is no mention anywhere for either bolt action or semi auto action about removing the ejector assembly.
Their gauges are meant to be used with a fully assembled bolt when working with semi autos.
If there is concern about the ejector throwing off the gauging, then I'd suggest that the issue is the ejector itself that likely has an issue such as something foreign in its bore or an over long spring or ejector proper preventing free or full movment.
Basically if the ejector does throw things off, its because it's not being allowed to be compressed down into its hole and flush with the bolt face as it should normally be able to do. Likely it screws up brass and has locking/chambering issues as a result also.
*it's been more than a couple years since I fondled that type so could be mistaken. But given the smaller diameter of the bolt contact point, it wouldn't make sense to make the gauge more delicate by doing such, especially in a .mil environment.
EDIT:
Iraqgunz, this would be the one you're talking about, correct?
http://www.ar15barrels.com/tech/headspace-gauge.jpg
Wasn't there a Bill somebody a while back that would regrind the Forster type gauges into the mil type gauge for a fee?
I know of the ones you speak.
They are turned down, well ground actually, on the end so that there's a round protrusion that is of smaller diameter than what the extractor and ejector pin represent on the bolt face. It just barely covers what area the 'primer circle' ends up on on the face.
Put them in, run the bolt forward, dump them out manually or suck them out with a stick magnet.
The Forsters are grooved with an extractor ridge and have a recess hole drilled in them to clear any potential firing pin protrusion, *which isn't present for whatever reason on the above described IIRC.
The only instance of bolt stripping that Forster mentions in any of thier instructions is in regard to bolt actions.
It is suggested that the extractor be removed from them to help get a better feel and free-er bolt rotation as the lever arm that the bolt handle represents can do a pretty good job of messing something up if worked too hard due to a numb feel.
There is no mention anywhere for either bolt action or semi auto action about removing the ejector assembly.
Their gauges are meant to be used with a fully assembled bolt when working with semi autos.
If there is concern about the ejector throwing off the gauging, then I'd suggest that the issue is the ejector itself that likely has an issue such as something foreign in its bore or an over long spring or ejector proper preventing free or full movment.
Basically if the ejector does throw things off, its because it's not being allowed to be compressed down into its hole and flush with the bolt face as it should normally be able to do. Likely it screws up brass and has locking/chambering issues as a result also.
*it's been more than a couple years since I fondled that type so could be mistaken. But given the smaller diameter of the bolt contact point, it wouldn't make sense to make the gauge more delicate by doing such, especially in a .mil environment.
EDIT:
Iraqgunz, this would be the one you're talking about, correct?http://www.ar15barrels.com/tech/headspace-gauge.jpg
Wasn't there a Bill somebody a while back that would regrind the Forster type gauges into the mil type gauge for a fee?
Good pic. That is a GI "Field" headspace gauge. I have checked HS on literaly thousands of M16 series rifles and carbines, and I have only encountered 2 or 3 M16s that failed HS. And those were training rifles with a LOT of rounds on them.
brzusa.1911
08-28-11, 11:12
Awesome, thanks all for the contribution!
Military GO and NOGO gages have the extraction groove intact, they are not rebated like the military FIELD gage is.
Military GO and NOGO gages have the extraction groove intact, they are not rebated like the military FIELD gage is.
There must be some other ones out there then, because every no-go gauge I've ever seen looks exactly like that "Field" gauge pictured.
The military does not use a "No Go" or "Go" gage for the M16 family of weapons. They use a "Field" gage only.
Military GO and NOGO gages have the extraction groove intact, they are not rebated like the military FIELD gage is.
GTifosi,
Yes, the gage you are showing is the military "Field" headspace gage.
The military does not use a "No Go" or "Go" gage for the M16 family of weapons. They use a "Field" gage only.
No, unit armorers use FIELD gages, higher echelons are issued full sets of gages. Want the NSNs for the gages? The dimensions? The prints?
No, unit armorers use FIELD gages, higher echelons are issued full sets of gages. Want the NSNs for the gages? The dimensions? The prints?
Correct. We are in between depot-level and unit level maintenance (sub-depot level).
No, unit armorers use FIELD gages, higher echelons are issued full sets of gages. Want the NSNs for the gages? The dimensions? The prints?
Yes please, and any TM’s that covers the use of them.
Unit armorers are not authorized to use any gages.
Correct. We are in between depot-level and unit level maintenance (sub-depot level).
So that would make you direct support?
Unit armorers are not authorized to use any gages.
True, the FIELD gage comes in even farther up the line.
I don't have time to type all this out again after more than ten years of putting out the same information online. Here's some pics.
[edit for OPSEC]
http://i13.photobucket.com/albums/a264/artweaker/Troubleshooting/FSCN3252.jpg
http://i13.photobucket.com/albums/a264/artweaker/FSCN3253.jpg
http://i13.photobucket.com/albums/a264/artweaker/Troubleshooting/FSCN3254.jpg
Yes please, and any TM’s that covers the use of them.
Unit armorers are not authorized to use any gages.
So that would make you direct support?
Yes. USAF Combat Arms Specialist. The only thing we don't repair are receivers. They go to Anniston or the AF Gunsmith Shop at Lackland. PS: Thanks for the pages from the TO (or TM for the Army)...
TO (or TM for the Army)...
TB in that case, Bulletin.
FYI- I was not a unit armorer and I have done GS/DS level work. We still did not have the gages. The only gages we had are the ones outlined in 9-1005-319-23&P. Is it possible that the info is dated?
I am going to see if I can locate my POC for TACOM and check with him.
No, unit armorers use FIELD gages, higher echelons are issued full sets of gages. Want the NSNs for the gages? The dimensions? The prints?
I have to eat some crow here. Apparently while I was on my last deployment, our gages went in for their PMEL (calibration) inspection and failed calibration. When the shop ordered replacement gages, the only gage that came was the field gage. My guys were told we are no longer authorized "Go" and "No-Go" gages.
Mmm, the humble pie tastes great...
I may be wrong, but I believe that those gages were phased out for all services across the board and the only authorized one is the ''Field'' gage. I am waiting for a response from RI.
I have to eat some crow here. Apparently while I was on my last deployment, our gages went in for their PMEL (calibration) inspection and failed calibration. When the shop ordered replacement gages, the only gage that came was the field gage. My guys were told we are no longer authorized "Go" and "No-Go" gages.
Mmm, the humble pie tastes great...
Where can you get a turned down field gauge? Since I have four uppers, I'm thinking one in the tool box might not be a bad idea.
billricca.com was selling the real deal. The website says that he is currently out of them.
Rumor has it that there will be some gage sets hitting the market soon.
Where can you get a turned down field gauge? Since I have four uppers, I'm thinking one in the tool box might not be a bad idea.
Is it possible
Doesn't really matter now does it?
billricca.com was selling the real deal. The website says that he is currently out of them.
Rumor has it that there will be some gage sets hitting the market soon.
Email him. The website may not be up to date. I got one a few weeks ago that way, although it may have been the only one had in stock at the time.
Did I miss something?
Doesn't really matter now does it?
I have plenty of gages already. I was posting that for the benefit of others.
Email him. The website may not be up to date. I got one a few weeks ago that way, although it may have been the only one had in stock at the time.
Powered by vBulletin® Version 4.2.5 Copyright © 2024 vBulletin Solutions, Inc. All rights reserved.