I know I can save big bucks by building my lower.  But is it worth building the upper too?  I'm concerned with headspacing.  Thanks.

-YJ

I passed this very same milestone myself about 6 months ago.

I decided to buy my first upper complete, but on my second build I wanted to be able to "save" even more $. The only problem is that I ended up breaking about even, because I am one of those nerdy types who always buys all the "correct" tools to do the job (because I like to buy tools I guess )

I say build it yourself...but not just to save the $, it gives you a great feeling to completely build your first gun completely from parts!! Plus you gain the knowledge of barrel removal and installation so you wont be one of the "afraid to change my barrel scaredy cats" in the future!

The point I am trying to make is that you may not save any $ on your first build, but any uppers you build from now on (after the tool investment) will save you some $$!!

This is your decision, as if you are any kind of tinkerer / mechanic - you know you can improvise tools pretty easily in a crunch...BUT...

I will tell you it is MUCH easier with the following tools:

Barrel wrench with square "cut out" for use with torque wrench
Upper action block  - this holds your upper securely and without scratching it while in a vise
Torque wrench - you will use this to get the correct torque on the barrel
Solid Bench Vise - to hold the upper with in the "action block"
*Go / No Go gauges - these will tell you if your headspace is correct and safe to shoot

*I have installed 3 uppers / new barrels / new bolts and have never had a bad head space issue.   Some say you do not have to worry about it, some say you would be a fool not to - I decided to not take any chances and know for sure

I bought all of the above tools new from various sources and I think it came to about $170 or so.

Hope this helps!

I've simply placed the upper inside a folded newspaper in a vise the last couple builds; no problems, just don't crush the receiver. You should only need the Armorer's wrench and pin punches to put an upper together.

Headspacing ought not be a concern.

Quoted: I've simply placed the upper inside a folded newspaper in a vise the last couple builds; no problems, just don't crush the receiver. You should only need the Armorer's wrench and pin punches to put an upper together. Headspacing ought not be a concern.

He is right yellowjacket - I installed my first barrel with an old sweater in the vice (I just could not wait for the action block to show up ) You do need to watch out in regards to crushing it as he said though...it can be done

To clarify why headspacing is not really a concern in terms of you assembling it:

The headspacing on the AR is set when the barrel extension is mated to the barrel.  When you buy a barrel, it already has the barrel extension attached so there is no way for you to adjust this.  When you attach the barrel to the upper reciever, it has no effect on headspacing.  

The only way you would affect this is if you were really advanced and ordered a barrel without the barrel extension attached and did it yourself (I'm not even really sure what the process for this is).

However, this does not mean you should not check the headspacing when the bolt is put into battery.  That is another discussion.

An Armorer should build the upper.

Quoted: An Armorer should build the upper.

Why?

There's really nothing that critical in the assembly of the upper.

The headspace was set to the standard at the factory when the barrel extension was installed on the barrel.

The worst that can happen---baring the extremely unlikely event that you get a wildly out-of-spec bolt that would cause excessive headspace---is that the barrel assembly isn't torqued into the upper receiver properly.  In which case you might have some accuracy issues.  The gas tube will keep it from unscrewing, so it's not going anywhere.

The only "danger" is---as others have already mentioned---that you'll crush or scrape up the upper if you use an improvised vise block.

I think markm was being facetious.

Quoted: I'm concerned with headspacing.  Thanks. -YJ

No matter if you build the upper or not, the barrel extension will be attached to the barrel from the supplier.  Either the bolt is going to headspace correctly or it's not.  Headspace is determined when the barrel is produced, and not on the completion of the upper.

Thanks alot guys.  This explains a lot of the mystery of head spacing.  A buddy of mine (same guy that gave me the BR fever) has all the tools I'll need (including head space gages).  I may still buy a barrel wrench and upper action block.  I ordered my stripped lowers (RRA) today, but they're back ordered!  I had almost decided to get a complete upper from Model 1, but if I assemble it myself I may do something different.  Any recomendations of sources for barrels?  I want to build a lightweight M4gery first.  I'm not planning to do any long range stuff with this one, but I want to keep open the option of heavier bullets.  Model 1 offers 1:8 twist and 1:7.7 (stainless).  Who else offers M4 profile barrels in these twists?  Thanks again.

-YJ

Go with Stag lowers from eaglefirearms.net, they should have some in stock.  They're just as good as the RRA lowers. :)  I have two in the closet waiting to be built up.

I'd recommend a Bushmaster,  LMT, or Colt barrel, as they're the only ones made from 4150.  LMT barrels are available from a couple different online sources.

Operation Parts has a great deal going on for KA RAS-II's.  $275, and they come with an extra 6-rib panel + foregrip.  Might make for a nice rail system on your build.

Who sells just an UPPER kit?  I have not been able to find one.

I have noticed that the cost of an entire kit is about the same as a built upper.  Assumimg that you built the whole thing it would only be about $500, i.e., $400 to Kieslers or FAC for a DPMS kit + $100 for the lower.  Not bad.

Quoted: Who sells just an UPPER kit?  I have not been able to find one.

Model 1 Sales sells just the uppers.

Quoted: I'd recommend a Bushmaster,  LMT, or Colt barrel, as they're the only ones made from 4150.

Marcos, first off, I'm not tryin to be an ass or bash or anything like that but.....Whats the difference between 4150 and 4140 metals? Besides "4150 is harder". I have a Model 1 M4gery and from what I understand it has the 4140 Chome lined barrel. I can see why the Mil would want a harder metal for thier barrels but whats the big deal of a civi havin a 4150 barrel? I know I'm not gonna shoot as much as the Mil is shootin. Yeah I'll go through my CMag quickly, but then she cools down afterwards. I don't sustain fire for a long amount of time, I'm not going full auto or anything. So I don't see a need for a 4150 barrel. I've seen other posts of people recommending 4150 barrels and the main thing I see is "they're harder". For a civi though, is it really needed? Or is it more of a "if you're gonna build it build the best money can buy" kindof a thing??

Thanks. Rat

-------------------------------------------------------------------------------- Quoted: Who sells just an UPPER kit? I have not been able to find one. -------------------------------------------------------------------------------- Model 1 Sales sells just the uppers.

Thank you, but a lot of people sell finished uppers.  I am looking for an upper KIT.  

The M1S ad in the current SGN says that their uppers are "Fully assembled, gauged, and headspaced."

Marcos, first off, I'm not tryin to be an ass or bash or anything like that but.

No worries, Rat.  I was looking for a 4150 steel barrel; that's what I wanted.  I wrote M1S to ask them if their barrels were 4150 or 4140.  They claimed they were 4150, but have told others they were 4140.  They continued to state '4150' when I inquired further.  When I mentioned that E.R. Shaw says they only make 4140 barrels, they elected not to respond.  

It's not the steel - it's the misleading customer service.  I don't know what I am getting for my money, and if their service is suspect on something so simple as 'what steel do you use for your barrels?', how can I trust them with anything more?

So my money will go elsewhere.  Bravo Company, Operation Parts, and Eaglefirearms.net have all received money that otherwise would've gone to M1S.  I spent more, but not only did I receive higher quality parts, I have confidence in my suppliers.

Quoted: Who sells just an UPPER kit?  I have not been able to find one. I have noticed that the cost of an entire kit is about the same as a built upper.  Assumimg that you built the whole thing it would only be about $500, i.e., $400 to Kieslers or FAC for a DPMS kit + $100 for the lower.  Not bad.

hardcase I've never seen an Upper kit like you describe.  I called RRA and asked them a bunch of questions and basically the reason you save money on building your own lower is you're not buying the rifle's warranty and you're paying a smaller FET.  The parts are still covered by warranty, but nothing related to the final assembly and functioning of the rifle would be covered.  This obviously makes sense.  The cost of assembling the upper is either not significant or not fully deducted from the costs of the individual parts.

In other words you don't save money building your own upper, but you can mix and match the individual components to get the exact rifle you want.  Plus have the satisfaction knowing you put the thing together yourself.  Thanks for all the input from everyone.

-YJ

Quoted: Whats the difference between 4150 and 4140 metals? Besides "4150 is harder".

That's the only difference.  4150 has a tiny bit more carbon which makes the steel harder and stronger after heat treatment.

-YJ