AR-15 Upper Build

[jkray]

I did a search for this but didnt find anything. Most talked about complete uppers. I got in on the Spikes Lower/LRB Upper group buy, and I dont know much about AR's. The upper is stripped so I will be building the whole rifle. I am good with the lower thanks to the AR build thread.

I do not know what I need (other than the obvious) and I dont know who makes good parts.

I want to make an M4 style rifle if it makes a difference at this point.
What I know I need right now for the upper is:

Barrel w/ Gas system & sight post
BCG
Buffer spring / tube
Handguards

So what am I missing and any info on what parts are good would be appreciated. I would say budget is not an issue because I plan on saving up to buy good parts as I go and expect this to take a good while to build completely.

Also I want my barrel to be as close to 16" as possible so my question on this is, can I buy a 14.5" barrel and put a flash hider on it without needing to go through NFA? Do I need to pin it? and if so, can I get one/do it in a way that I will eventually be able to attach a suppressor to it?

I know there are a bunch of noob questions here but this is my first forray into AR's and I want to get it right and legal.

Thanks

 

[DZ]

I am not very familiar with upper builds, but will tell you that it requires more specific tools.

You will need, at the minimum, a good vise block for the upper. Linked is the one I bought for changing the rail on my upper.

A barrel nut wrench is required to install the barrel nut. Depending on the rail you buy, this may be proprietary. It may be included with the rail or you may have to purchase it. A torque wrench is recommended for installing the barrel nut properly.

Depending on the barrel and gas block/ front sight post, you may need a good set of pin punches and a proper way to clamp your barrel in place to drive in/out the pins. This can be extremely difficult. You may need a set of roll pin punches as well, depending on the gas tube set up you go with.

You can buy and 14.5" barrel and add a muzzle device long enough to get you >16". This must be permanently installed. I recommend having Chad at Scott's Gunsmithing do this. He did an excellent job on mine. Be certain not to violate any NFA laws. There seems to be quite a bit of contradicting and misleading info on the errornet regarding construction of an SBR and intent to construct. Personally, I wouldn't let a <16" barreled upper hang around a lower receiver too long without having it pinned&welded to >16".

Unless you already know exactly what suppressor you want, you may just want to go with a 16" barrel. Otherwise, you may end up having to destroy the muzzle device you had permanently installed to switch it out with whatever device is compatible with your suppressor.

In addition to your list, you will need a dust cover and a forward assist, if not included with your stripper upper. Some come with them, some don't.

Do lots of research on what you want and on every step of the process. If you are mechanically adept, it shouldn't be too hard if you have the correct tools.

 

[BradMacc82]

DZ covered a lot of the bases pretty well.

Nice piece of info to have is something another of our AR Guru's (Forest) posted a while back - Army Technical Manual.


View attachment 58253

 

[erwos]

DZ speaks the truth. I'd strongly recommend just getting a real 16" barrel with an A2 flash hider. Not much longer, and saves you a lot of hassle. Plus you get a bit of extra velocity from the extra barrel length.

 

[jimbobborg]

If you want the shorter barrel, I'd suggest you get a non-threaded 16" barrel to build it, then take it to your local gun smith to shorten, thread, and install the flash hider. That at least keeps you legal with no "constructive intent" crap to deal with.

 

[jkray]

RE: NFA

I know all about the NFA laws. The stripped Upper should be coming sometime in June and the lower won't be here till Spetember sometime. So if I got the 14.5" barrel I should be ok for a month or so without having "constuctive intent" which will give me plenty of time to get the flash hider pinned. on the other hand it does make sense to just get the 16" barrel but i'm not sure if I want to have the extra 2+" out in front as this will be a HD rifle and I wand it to be as short as possible for ease of manipulation

On a side note I am not thinking of clearing my house with this but more so that my "safe spot" in my house for bunkering down in is a little tight and i figured the shorter the rifle the easier it would be to manipulate in this spot.

Back to the build.

I know nothing about muzzle devices. is there one that is "universal" for suppressors or are they generally proprietary? Its not that big of a deal really I was just trying to think ahead. If I need to buy another rifle to put a suppressor on.... oh well

 

[jimbobborg]

A 16" non-threaded barrel would let you choose which muzzle device you want to use. Say you wanted to use the brake/flash suppressor I bought, an AAC. It's pre-threaded outside for an AAC suppressor, and it's about 2" long. Now you can cut the barrel back 2" and get it threaded for your muzzle device. If you buy one pre-cut and threaded and you wanted to get a longer muzzle device, you'll go past the 16" total mark you wanted.

 

[jkray]

A 16" non-threaded barrel would let you choose which muzzle device you want to use. Say you wanted to use the brake/flash suppressor I bought, an AAC. It's pre-threaded outside for an AAC suppressor, and it's about 2" long. Now you can cut the barrel back 2" and get it threaded for your muzzle device. If you buy one pre-cut and threaded and you wanted to get a longer muzzle device, you'll go past the 16" total mark you wanted.

Good idea. I think I will just get the 16" barrel. Like I said its not that big a deal and since I have never owned an AR, I probably won't even notice the difference. Also this way it seems I have a few more options as to what I can do. Thanks guys!

Ok so far I now know I need:

Barrel w/ gas system & front sight post
BCG
Forward assist
dust cover
buffer spring / tube
handguards
Vice Block
Pin Punches

Anything else?

 

[BradMacc82]

Barrel wrench.

Buffer system should've been taken care of when you did the lower, but if it hasn't then yeah..., you'll need those parts...

 

[sailskidrive]

I would go with a low profile gas block; they only require an Allen key to install verses dorking around with punches and hammer stuff. Also, this way you could pair the upper with a nice free float tube.

 

[DZ]

I know nothing about muzzle devices. is there one that is "universal" for suppressors or are they generally proprietary? Its not that big of a deal really I was just trying to think ahead. If I need to buy another rifle to put a suppressor on.... oh well

There are a couple of suppressors out there that work with the A2 flash hider. There are also a few other brakes and flash hiders out there to work with suppressors that work with the A2 suppressors. The Gemtech HALO is one of the compatible suppressors and I believe KAC makes one as well.

 

[erwos]

on the other hand it does make sense to just get the 16" barrel but i'm not sure if I want to have the extra 2+" out in front

I think it's only an extra inch? The A2 FH is 2" long, but remember that half of it is on top of the barrel when it's screwed on. An extra inch is going to make zero difference when it comes to maneuvering; chop that bad boy to 11.5 or less, and then you've got something extra maneuverable.

 

[jkray]

You guys are great! thanks for all the info! Now on to barrel manufacturers... who makes a better than average barrel? doesnt need to be the best in the world but still needs to be better then middle of the road?

 

[erwos]

I would look for something chromed with a 1:7 twist. The new hotness is the FN hammer-forged barrel that PSA and some other places now offer. Unlikely to make a difference in practical use, but might enhance resale value.

 

[huesmann]

Charging handle, anyone?

 

[ASM80]

I used a BCM med gun fighter for my upper. It's nice, although i do not have the experience to compare it to anything else. For the barrel I have a DD med length 16" carbine and love it.

 

[sailskidrive]

Definitely the BCM mod 4, Black Rain Ordnance makes an even nicer handle but it is about $100 which I think ridiculous.

 

[jkray]

What is the difference between Hammer Forged and Button Swaged Barrels?

 

[tsmith1499]

Also being one that is doing their first AR build this is a great thread and very helpful. I also suggest checking out the BRownells videos online, They are pretty informative also.

 

[Indiana Jones]

If you choose a YHM quick detach suppressor mount, you can have the barrel cut to 14" even, and this will make the overall length of the barrel after pinning, 16.1". The ATF uses a wooden dowel for measuring barrels, the extra .1" is just icing on the cake of CYA. Every person who has seen my rifle has mistaken it for an SBR, it looks THAT short and cool. I'm really glad I had it done.