Do blank cartomizers contain primer? I've noticed that when using cartomizers with my 510 clone, I get a "gritty" feeling in the back of my throat (almost like I'm sucking on the outlet of a shop vac, lol) that doesn't seem to happen when I'm direct-dripping with the same juice on an atty that I've already burnt the primer off of. At first I thought this was the throat-hit everyone talks about, but from what I gather I should be getting MORE TH from direct dripping, not less.