I’m new to AR’s and am thinking of building my first one. I have read (on AR15) that you do not need to headspace if the parts are new?? Is this true?
If I buy a new bbl and upper and bolt carrier etc… and just put them all together, there is no need to headspace? If headspacing is needed, how do you do it??
Thanks!
Jon
As with most military weapons… if the parts you buy are made to the correct specifications, the headspacing should be correct. The rifle is designed so that parts can be mass produced by several different companies over many years, and all parts fit and function in the field.
That said, notice the “if” and “should” – headspace gauges are avaialble from the usual sources (Midway, Brownells, etc) and any good dealer or plumber will have a set… It would not be a bad idea to have it checked of course; if you purchase the barrel and bolt from a dealer on here, ask them to check HS before they ship. If you pick parts up elsewhere, find a local smith or shop and ask them to check HS (and see how it is done at the same time)… it takes all of a few minutes and I would imagine that any shop would be more than happy with a box of warm donuts in return for the service 
In any case, you should examine the first few cases fired from any rifle… a fired case can tell one a great deal about what is going on with the gun.
Thanks!! It appears that putting one of these together is not all that tough!
I hope that is true! 
Seems like it could become an addicting hobby!!
Jon
thats why they call it BLack Rifle Deseise or brd welcome to the club
Thanks Sweep! I can tell it’s gonna be an expensive club!!
Although it’s not required I check the headspace when assembling an upper. I use a USGI Field gauge which just checks for excessive headspace.
If you know how to read them…
I have gathered up a small collection of headspace info here
Going through my 223/5.56 gauge collection, I found I have the following:
1.4636
1.4666
1.4696
1.4736
1.4740