Starting an AR Build, some ?'s

[gadgetguy1288]

Well, I was gonna buy my first, but I walked into a local shop while on vacation, and found a stag stripped lower for $115, so I picked it up, along with a stag lower parts kit. I plan on buying either a magpul MIAD, or a hogue grip, and upgrading the trigger at some point in the future. Im building a Varmint type of setup and i want either a 20 or 24 inich barrel(Im looking at the Stag model 6h and RRA Varmint A4) and im undecided on a stock, Im currently looking at the ACE FX Skeleton Ultralight, and Magpul PRS.

I, also want to get OD green on the Stock, Grip, and Handguard, Thats why im leaning towards the RRA upper as i can order it with a green Handguard.

Questions:
1. Will a magpul MBUS work as a BUIS(i noticed that the flat top is a little higher than the front sight base, or so it looks)

2. Will I have to buy s buffer as well or will it come with the stock?

3. How do I know if I need a Mil spec or commercial Stock?

Im sure ill have more questions as this thing progresses but thats about it for now, Thanks!!

 

[Bartholomew Roberts]

1. Will a magpul MBUS work as a BUIS(i noticed that the flat top is a little higher than the front sight base, or so it looks)

You have a railed front sight base? If so, then the Magpul MBUS will work as a rear sight; but the polymer sight is not a good choice for mounting to a hot gas block. You need to be aware there are two different types of detachable front sights - those designed to mount to the gas block and those designed to mount to a free-float rail. The free-float rail sights will be too short on the gas block without a riser.

2. Will I have to buy s buffer as well or will it come with the stock?

It should come with the lower parts kit.

3. How do I know if I need a Mil spec or commercial Stock?

Stag and RRA both use the commercial tube. Typically a manufacturer will advertise if they use the military tube.

 

[sholling]

2. Will I have to buy s buffer as well or will it come with the stock?

It depends on the stock. If you're buying a kit complete with a tube then it may come with the kit. If you're buying separates then you'll have to buy it separately.

3. How do I know if I need a Mil spec or commercial Stock?

It depends on the tube you buy to go with it. Either should fit the lower receiver.

While you're shopping you might want to add White Oak to your list of uppers. Their varmint uppers are reasonably priced but they are .223 not 5.56 which limits ammo choices.

 

[zenmtnman]

You're off to a good start.
It sounds as though the carbine buffer still needs to be purchased, as you'd probably know if you had it already.
As for uppers...I wouldn't worry about the OD green handguard. You can buy them for about $20-30 online from several places, and you don't want to limit your upper choices. Swapping out handguards/grips/stocks is pretty easy. As for Commercial vs. Mil-Spec...its about diameter. Most manus makes their aftermarket stocks in both, so either is fine. I haven't heard of a function drawback for commercial yet...Anyone else?
I would recommend a mid-length gas system if you're going for a 16" ish barrel, as its a little easier on the action, but again, its personal preference.
I've got both a CMMG upper in 16 (midlength) and a RRA (midlength in 6.8spc) and am impressed with the fit and finish of both. You also can't go wrong with Noveske, LMT, Colt, etc...but I don't know what your price range is.
I agree with Sholling that you'd probably be best served with a 5.56 chamber, as you'd be able to use both 5.56 and .223 ammo, and White Oak makes good stuff too.
Poke around gunbroker. You can likely get an upper for around $500-700 these days, shipped right to your door. No need for an FFL for that.
Keep asking away, there's lots of us here to help!

 

[Alleykat]

I recently built a varmint AR, using a 20" bull RRA barrel, RRA flattop upper, stag lower and JP fire control. Can't imagine why you'd need back up sights on a varmint rifle. I don't use back-up sights on any of my ARs, but that's just a matter of personal preference.

I'd go ahead and buy a good trigger. I like the JP setup, but also own an AR with the RRA N.M. trigger...decent, but not as good as the JP. There are also Jewels, Geisels (sp?), etc., etc.

I'd suggest that you also build the upper. A $37 DPMS free-float tube will make for the same accuracy as a $400 Rambolista f.f.t.