Wow, can't believe there is actually something Ruger related that is unknown here. Actually it is questionable if Ruger ever licensed this product, I guess you could look at it as being that much more collectible.
I'm putting up a link to a gallery I made. The Stainless GB Folder in the pictures is a real Ruger, the Blued Short Folder AC556 is the Replica that fires a blank cartridge called a Plug Fire Cartridge.
I learned of these replica firearms a number of years ago, they are Chinese or Japanese made, and the AC556 is probably around 20+ years old. I have never seen one for sale before stateside, there is a European website that sold one and still has pictures on line as well as a video,
http://www.modelguns-worldwide.com/ruger_ac556.htm
As you can see from my pictures the rifle is exceptionally realistic, weighs nearly the same, and functions nearly identically to the real rifle. Field Strips into same basic components. Made of mostly heavy diecast metal, some steel, wood stock, plastic handguard, Steel 30rd Magazine. Came with 4 blank cartridges that have to be reloaded with special firing cap charges, they are available online but I have no desire to actually fire the rifle.
The story behind this one is that I just bought it off of Gunbroker, I jumped at the chance as I have never seen one for sale before and used the buy it now option to grab it, the auction was only a couple hours old.
Unfortunately the seller was less than accurate in his description of the rifle. He did disclose that the rifle would only fire semiauto as a piece was worn out in the full auto fire mechanism. He listed it as "very good condition" I would rate it as "used" and possibly non-functioning but excellent as a display piece or prop. It has a bit more wear than what is obvious in the pictures, the flash hider is bent a bit out of round and the folding stock has a lot of play in it, not unlike some real Ruger folding stocks.
Anyways, a very unique and fairly rare piece, want to see if anyone is interested in it, I'm a AC556 fanatic and have a KAC-556F in transfer at the moment. I would keep the Tanaka AC556 if it was in excellent condition, it is by no means worn out or junk but I am keeping my eyes open for a much better example.