The protank does not like hard draws. You have to draw slowly or you will definitely get dry hits or gurgling/flooding issues. You can partially remove some of the "flavor wicks" to increase the feed to the coil, but eventually you hit a point where too much wick removed will allow too much liquid into the center and it either gurgles into your mouth or drops into your PV.
Dry hits with all the eliquid on top of the atomizer?
Uh.....no
I can hit mine super hard....hits fine.....the pg /vg ratio you are using is fail..not the delivery system
