Is there a link to an actual anti-gun site where this was posted or is this solely an invention of the gun guys there? I guess using the term "anti-gun" is a clue.
Looking at the picture, is that supposed to be pump action? I can't see where a mag well would go. I guess tube-fed is a possibility.
On the other hand, I will assume 20 clips equals 20 - ten round .223 stripper clips. A 200 round mag would be nice though it might weigh a bit.