Mig one shot primer question

That is Stynylrez rebadged, which is the best acrylic primer going, but there are caveats. 

You need to shake it like it owes you money. Like for 20 minutes. Actually, when you get it, unscrew the cap and stir the paint around on the bottom, thrown a stainless steel ball or nut in there, then shake it for 20 minutes. I'm serious. If this stuff is properly mixed it gives you problems. 

If it was ever frozen, like during shipping, it's useless. 

It really needs at least a .4 needle airbrush. Even larger. 

Practice proper trigger discipline - air on, paint on...paint off, air off - to reduce the chances of tip dry. 

I've used the stuff with no problems. Maybe try turning up the PSI a bit more might help.

The only advice I can give on this is to use a different primer, such as Mr. Surfacer or Tamiya Surface Primer.  Both of those spray through an airbrush with no issues.