To Headspace or To Not Headspace

[bettingpython]

No.

At most a go no go gauge check, but if it's new I would just go shoot it and quit fretting.

Adjusting AR headspace is a complex task once the barrel is built up. You need to remove the barrel extension and machine off some barrel on the chamber side to "short chamber" the barrel. Then you need to reinstall the barrel extension. Since the barrel extension (feed ramps) and gas port need to be oriented in given positions and the barrel extension is threaded on it invloves lots of hand fitting and machining to get them right. You then cut a new chamber in the barrel, measuring your headspace as you go with gauges and the bolt you are going to use for the rifle. This cannot (should not) be done with a chrome lined barrel. Now that being said, a previously properly headspaced AR that is now out of spec probably has a worn out bolt (bolt lugs worn or fatigued) and fitting a new bolt and checking it with headspace gauges, will probably fix the problem.

 

[Keelty]

No from me. If you buy your barrel from an established company, they have already done everything for you. The only problem you can have is a worn out bolt which i think was already said above.

 

[RKM]

No need. I've put a lot of them together from various manufacterers with no problems.

 

[Shriner]

Ar.com basicly said rock on without headspaceing if you are not using chi-com pot metal bolts and barrels.

 

[aeropb]

Don't do it its a trap

 

[Boehlertaught]

I'm new to AR's too, but my experience with other firearms says the head space should be checked. Some barrel mfgr's, e.g. Krieger, suggest you send them your bolt and the will head space it to the barrel you buy from them.

 

[HiredHand]

So, it seems that most people are confused about headspace gauges, what they mean and how they are used.

Gus Fisher explains:

The “ GO “ Gage: This is the shortest Headspace Gage and is used to check and ensure the chamber has the MINIMUM headspace necessary for reliable and safe operation for even the longest cartridge case that is still inside manufacturing specifications.

The “ NO GO “ Gage: This is the most widely MISUNDERSTOOD Headspace Gage and causes the most confusion to a whole lot of folks. I can’t tell you how many times I’ve heard or seen incorrect things said or written about this Gage and sometimes by people who SHOULD know better. This Gage is used by Arsenals or gunsmiths/armorers when they cut the Headspace in the chamber of a rifle along with the GO Gage. You have to cut the Headspace deep enough so the GO Gage will fit without showing additional friction on the bolt. That gives you the Minimum Required Headspace. You then use the NO GO Gage to ensure you don’t cut too much Headspace when you first chamber a rifle. Headspace may increase as much as one or two thousandths of an inch ( .001” to .002” ) during the entire life of the barrel until you shoot the lands out. SO you have to have a NO GO Gage to show you where to stop cutting and ensure there will not be too much Headspace throughout the entire life of the barrel. (IOW, when you stop cutting the headspace - there will still be a few thousandths of an inch before you hit the Maximum Headspace length.) The NO GO Gage is NOT the maximum gage and it is NOT the Gage that tells you the Headspace is too much or too deep. If you don’t cut Headspace, you really don’t even need this gage to check for safe Minimum and Maximum Headspace.

The “ Field Reject “ Gage: OK, THIS Headspace gage is the gage you use to check for Maximum Safe Headspace even when you get the shortest cartridge made to specifications. If the bolt closes on this gage without additional friction than before you had the Field Reject Gage in the chamber, then the barrel is UNSAFE and no one should fire the rifle until the barrel is pulled and a new one is installed. If one wishes to have the two necessary Gages to check Headspace, you need this Field Reject Gage and the GO Gage for any individual caliber.

You can find the rest of the article here, http://m14forum.com/gus-fisher/66601-little-bit-everything-do-headspace.html