Sand-blasting cabinets?

I have the same setup and have had good service from it. I've also had decent customer service when I have gone into the store with a problem. I would almost bet they would exchange the gun with another one in the store if you just took the gun back in.
Still, take the ceramic tip out and without the tube in the sand see if you get more air flow out the nozzle end.
I would still like to see a better pic of the gun.
C