I can't stop thinking about my dream rifle.  It would be an AUG/MSAR upsized to handle .308 using SR25/DPMS/Magpul 20 LR magazines, 18" or 20" barrel.  Hard hitting, compact, piston driven, lightweight, great balance, etc.  Would this not be the perfect all around rifle?  Almost every other platform out there has been upsized to shoot .308 (SCARL/H, ACR/Massoud, AR15/AR10, Sig 556/716, HK93/HK91).  While I like the RFB, it just doesn't do it for me, especially looks/possibly quality wise.

Besides the current state of the economy, is there any reason why an AUG in .308 could not be produced?

You would have to upscale the gun a bit and rework the layout to "slide the grip back" for a manageable LOP, but other than that there isn't any reason it couldn't be done.

Trust me, you aren't the first guy who has thought about this, I think a lot of us have dreamed or mused about it once we fall in love with the AUG.  

You could compromise and get a Keltec RFB.  Not a aug but its a bullpup.

OTOH, it would be relatively easy to set up the AUG to handle 7.62x39. Microtech did it for the MSAR, though I don't know how well it actually worked. One problem I heard about is finding reliable magazines. The AR-style mags don't adapt to feed 7.62x39 well. The stock of an AUG, therefore, would have to be redesigned to take AK mags instead. Not an insurmountable problem, but probably not something we're very likely to see either. Too bad. I think an AUG in 7.62x39 would be a hoot to shoot. Maybe one day I'll find one of the 7.62x39 kits for my MSAR? (Oh, look! A flying pig....)
I have an RFB, and I really like it. I load my own ammo, and the forward eject feature is a dream since I don't have to chase the brass all over the range. It all ends up piled at my feet. AND the RFB doesn't bash the brass up like an AK or H&K platform, or the FAL. After shooting my RFB for a while, I decided I liked it so much that I wanted an RFB in 5.56x45. But it's clear that isn't going to happen any time soon. KelTec has a hard time meeting demand for the 18" barrel RFB in 7.62x51 as it is. So I had to *settle* for an MSAR E4, and then when I finally found one an AUG A3  

 
 
 
 
 

You didn't even read his full post, did you?

There are blueprints for a .308 AUG out there.

I have 5 7.62x39 AR mags and they work alright, I had problems with them at first with feeding and such but after a few uses they are good to go, they are ASC and C products.

Just find a 6.8spc  MSAR Conversion, there's a few out there somewhere. As close as you'll get ;)

I have both a Geibersjager and the RFB and while the MSAR is a good gun the RFB is the better of the two. It is .308 and uses all kinds of ammo and the handling and accuracy are exemplary. The CS at Kel-tec is excellent like when Dave was at MSAR. The trigger on my MSAR is great now that the RATWORX trigger pack is in but the RFB trigger is like that from the factory. The MSAR is too finicky when it comes to ammo, like steel case. Alot of failures to extract, the mags are specialized and it needs a different bolt for ambi use. The RFB is truly ambi and uses FAL mags and instead of polymer between your face and the breech you have 3.0mm of steel plate. FYI in the OP the RFB quality is excellent.

I think the RFB is a piece of junk.  I have the exact opposite opinion of everything you just said.

My RFB, was waaaayy to finnicky with all of the ammo I used, was too heavy, used ancient mags which were hard to find, was a bitch to break down and was a general PITA.

My MSAR eats up russian steel case, uses great mags, its lighter and handles better.  It tends to break bolt sleeves though...grrrr...

Wish in one hand, and well you know the rest.

RFB in the other?