I'm thinking of buying a bunch of this just to get the stripper clips it comes on (they fit an Uzi mag loader I bought).  The Cheaper than Dirt website says it won't cycle a semi auto, but does spit out a plastic "bullet".  I have heard from the guy who sold me the loader that he has a special barrel that lets him shoot this stuff reliably in his Vector Uzi.

Questions:
1.  Has anyone actually shot this stuff?
2.  What good is it? Is it really worth the trouble to shoot?
3.  What "special barrel" is needed to make this ammo function in a full auto or even semi auto mode?
4.  If I buy the stuff by the case (about 900 rounds) just to get the clips, does anyone here want the ammo?

I've shot this stuff in my Kel-Tec Sub2000.  It goes bang every time, but it smells like burnt plastic.  It won't cycle in my carbine, but is good for malfunction drills and the like.  May also be good for teaching people to shoot - much less recoil and noise, but you aren't constrained to a .22.  Once they are comfortable with the gun you can then switch to the real stuff with a little more confidence.  The steel BB in the nose of the bullet travels a ways but I haven't put it on paper to get a look at accuracy or trajectory.  Also seems to be rather dirty.  I dont know anything about the special barrels to make it shoot reliably.   The stripper clips are pretty neat, six rows of six for a total of 36 rounds per stripper clip.  The swedish sub gun mags all held 36 rounds.  Someone here said the metal BB can cause damage to the lands of the rifling inside the barrel, but I can't vouch for that - just someting to consider.  

Hope this helps.

that stuff shoots ok in my Marlin 9mm Camp carbine. Accuracy is nothing to speak of, but it will function the action reliably. Kinda like a high powered pellet rifle??? I haven't really figured out a good use for this ammo yet???

After a little more research, I've found two good uses for this stuff:

1.  I can get the clips it comes on at a dirt cheap price, which is all I really wanted in the first place
2.  With the special barrel, I can shoot low recoil 9mm for 2 cents or so a round

So, I found a guy who makes the barrels.  They cost about $135.  He ran out of the last batch, but is working on more.  I figure if I buy 4000 rounds of the plastic/BB ammo (total cost just under $100) I can have hours of fun just blasting away at things, saving about 7-8 cents a round over 9mm.  That would be a savings of $280-$320 in ammo for a $135 barrel.

One concern is that the supply of this practice ammo is limited, and when the surplus stuff runs out, the special barrel is worthless, but I don't really care because if I can save a few hundred bucks now to have cheap blasting fun, and when all is said and done I have the ammo clips I really wanted in the first place, I have a hard time seeing any downside at all.

You is not supposed to fire that stuff in a std 9mm barrel.  The BB will damage your barrel, common knowledge at Subguns and Uzitalk.  There is a fella thatt advertises 5mm subcaliber barrels for use with that ammo.