AR 15 Headspace

[PigPknHeat]

I am wondering if the headspace of an AR 15 can be adjusted without buying new bolt, barrel, carrier, etc....

I have an oppurtunity to buy an upper put together from different manufacturers from someone I do not know from a hole in the wall, and want to check the headspace when I get it. If it is out of spec what are my options?

Thanks guys,
MP

 

[Mattyd7]

It is pretty much impossible to adjust the headspace on an AR-15. It is determined by the dimensions of the bolt and the barrel extension. Chances are you will be fine, it is pretty rare for the headspacing to be off unless the bolt or barrel were made by a questionable manufacturer.

If you have a problem with headspace, you best option is to buy a new bolt (don't need a new carrier) and try that first. That's cheaper than a new barrel. If you try multiple bolts and none are working, then you will have to consider swapping the barrel. To save some money, you could try bolts out of other guys guns to start the troubleshooting and isolate the issue. Just don't use ones that are really old, since they are bound to have wear.

I won't go into it here, it's all over the web, but make sure you use the right headspacing gauges for your rifle. If you are using .223 gauges, it is not as straightforward as you'd like it to be, since the 5.56mm chamber is slightly different and those few thousandths might give you a false failure.

 

[W.E.C]

From the free advice is worth what you pay , ar parts are crazy expencive , and the junk is as pricey as the quality stuff. Buy matched parts from the best quality makers you can afford.

 

[Mr. Brownstone]

CLYMER HEADSPACE GAUGES - NO-GO | Brownells
184-000-036WB
NO GO, 5.56 NATO Mfr Part: NG556NATO

It is pretty much impossible to adjust the headspace on an AR-15. It is determined by the dimensions of the bolt and the barrel extension. Chances are you will be fine, it is pretty rare for the headspacing to be off unless the bolt or barrel were made by a questionable manufacturer.

If you have a problem with headspace, you best option is to buy a new bolt (don't need a new carrier) and try that first. That's cheaper than a new barrel. If you try multiple bolts and none are working, then you will have to consider swapping the barrel. To save some money, you could try bolts out of other guys guns to start the troubleshooting and isolate the issue. Just don't use ones that are really old, since they are bound to have wear.

I won't go into it here, it's all over the web, but make sure you use the right headspacing gauges for your rifle. If you are using .223 gauges, it is not as straightforward as you'd like it to be, since the 5.56mm chamber is slightly different and those few thousandths might give you a false failure.