Well, I've made the instructions sooner that I hoped for, so here you are! If the instructions aren't clear or I messed up the pictures or whatever, please let this know me, I'll fix it for you.

About the gun: As I said, CoD players will know it, and I start building right after i saw it for the first time, because it's such a fun gun to make on your own. When I started, I discovered it's a complex gun to design and not easy to built at all. The barrel and the stock mainly, the final product of the stock is filmsy, you can fill it up. I personally don't do that, I hate heavy stocks.
I've chosen for a 4-layer barrel, so the bullet has enough space.
Now, some good and bad stuff about the gun:
Good stuff:
- Looks good
- High capacity magazine
- Real trigger
- You can wear it, it isn't heavy at all
- 4 layer barrel

Bad stuff:
- the muzzle break is too big
- non-removable magazine
- sometimes the bullet get blocked in the barrel, at the orange connectors
- the pin guide sucks + the trigger block isn't placed that much back. (Far enough in MINE opnion:))

(All these 'bad stuffs' can be removed, for the barrel-problem you can use sharpened rods, like I always do.)

Now, let's get building!
Again, if you've problems, please tell me.

Oh yeah, if you've made this gun, it would be pretty cool if you post in picture so I can add it in the intro. Just PM or comment me.

Step 1: The Stock.

The stock of the gun!

The top part is filmsy, you can add stuff in there, it's all what you prefer.
I'm really sorry, the instructables at this step aren't really clear :S
You don't have to put all the black/green and white/silver rods in it, this makes it too massive and your never can take it apart :D

Step 2: Handle, Trigger and Trigger Guard.

Maybe the 7-way connectors are really annoying when you're holding it, but I get used to it.

Step 3: Barrel, Magazine, Ram Rod (guide) and Connecting the Stock. Yeah That's a Long Step Name, Isn't It?

Step 4: Front Barrel, Muzzle Break and Bipod.

Sorry, I was too lazy to take the front barrel apart. Just look good, I can't imagine it's too hard.

If you gonna connect the barrels, remove the 4 connectors as show (the yellow boxes), connect them if you've connected everything

Step 5: Scope.

If you like this scope I'll post clearer pictures but it sucks :P
Make your own if you want, but anyway, here are some pics:

Step 6: Finishing Touches.

Time to show you how to put the rubber bands, some tips etcetera.

Step 7:

Great job! You've built the Barret 50 cal.!
Have fun!

lol this cool squirrel was killing our plants while I was making pictures :P
(and no, I didn't shoot it ;D)