Last night I assembled my pile of AR-15 parts into a near rifle.  I say "near" because I still need a barrel and the upper parts kit was missing the two pins needed for the A2 rear sight (kit came with two forward assists though).  I had to build the upper based on what "looked and felt" right since I didn't have a step by step procedure for that.  Everything seems to work right.  Cock the hammer, pull the trigger and the hammer flies forward (I catch it with my thumb).  Safety selector works, bolt catch works, mag release button works.  On the upper end, the charging handle pulls the bolt back and the FA moves the bolt foward in small increments.  The dust cover opens when the bolt moves forward or rearward and latches securely.  Assembly took less than an hour and was straightforward.  What could I have missed?  BTW, this was the first time I've been inside the guts of an AR.  I don't even own one and have probably put fewer than 50 rounds through the platform ever.

My AR: Stag lower, LAR Grizzly A2 upper, RRA LPK, DPMS UPK, Generic 6 POS stock (If I decide I like collapsable stocks, I'll probably upgrade it with a better one later), Hogue FF Tube and pistol grip, RRA Bolt/Carrier.  

I'm going to swap the standard CAR buffer with a 9mm buffer.  I haven't bought the barrel yet, but it's likely going to be a chrome-lined 16" heavy barrel with 5.56 chamber.

Chris

Yes it is.  Extra/too few parts make it a little tough though.

What type of mountain bike do you have, mountain biker?

Yes, it really is that easy. Building an AR is merely "parts assembly" and is much easier than most people think.

It sounds like you got everything put together OK.

- Did you use grease on the receiver extension and barrel nut threads (aluminum on aluminum tends to seize)?
- Did you put the disconnector spring in the right way (big end goes into the trigger)?
- Did you put the hammer spring legs ON the trigger pin?
- Perform the function check for the lower to test the disconnector and make sure it works. Cock hammer, pull trigger (catch it so it doesn't hit the receiver or bolt catch). Then while still holding trigger back firmly, recock the hammer. Does the disconnector hold the hammer? If so, release the trigger. The trigger sear should now catch the hammer after the disconnector lets go of it.

Aside from that, there isn't too much that is tricky about building an AR-15, except for the front sight block. If I were you, I would get a 'barrel assembly', rather than a blank barrel and try to fit a front sight block to it, since the FSBs and barrels are drilled as an unit for the taper pins. The price of a barrel assembly usually doesn't make fitting FSBs to blank barrels an attractive proposition. (By 'blank barrel' I mean one that has already been drilled for taper pins but has had the FSB removed).

Quoted: What type of mountain bike do you have, mountain biker?

98 Klein Pulse (Trek built, but still lighter and stiffer than a Trek, better geometry too).

I haven't ridden in a couple years though.  Having a baby does that to you sometimes. :)

Chris

b0ne,

Yes.
Yes.
Yes.
Function check on the trigger/disconnector performed appropriately.

I said barrel, but I really meant barrel assembly.

Chris

Quoted: Quoted: What type of mountain bike do you have, mountain biker? 98 Klein Pulse (Trek built, but still lighter and stiffer than a Trek, better geometry too). I haven't ridden in a couple years though.  Having a baby does that to you sometimes. :) Chris

Sweet.  I have a Gary Fisher Paragon that I got a few years ago.  It has held up very nice.  I need to ride alot more than I do, though.

Quoted: b0ne, Yes. Yes. Yes. Function check on the trigger/disconnector performed appropriately. I said barrel, but I really meant barrel assembly. Chris

My bad. When I saw you say 'two pins', referring to the rear sight assembly, I misread that to mean the two taper pins for the FSB, and thought you were assembling a barrel.

Sounds like you've got it down pat. Happy shooting!

you did good mtnbkr  now get that thing barrelled up and shoot it.

combat lego's.

Apparently, It's really "that easy"

Quoted: combat lego's.

 Excellent terminology!  Now I can say I still haven't outgrown my legos!

I said in a earlier post, this really is lego's for adults.

Of course if the liberaly looked at it that way we would either have full-auto legos, or REALLY unhappy kids.

I got a specialized epic M4 frame (2003 model).  Guess I got 3 black M4's.  IMHO, mountain bikes are harder to work on

Quoted: IMHO, mountain bikes are harder to work on

And they require more tools.