I have noticed this too, carts being inconsistant in build. Some have less padding where the center tube sticks above it, some have the heating element sticking out a bit so it's closer to the outer casing etc.
I just washed out 10 cartos in boiling water, out of 5 filled exactly the same way with the same amount of Menthol liquid, 2 of them work perfectly on the standard size batteries, as in lots of vapor, good throat hit, with little effort. The other 3 however, no matter how tight or loose I put them on, barely make much vapor at all, even on a PT, and seem a little harder to draw.
Maybe these "premium" cartos they are getting in have been made better by a better company, might have to buy a couple packs on next order.
I just washed out 10 cartos in boiling water, out of 5 filled exactly the same way with the same amount of Menthol liquid, 2 of them work perfectly on the standard size batteries, as in lots of vapor, good throat hit, with little effort. The other 3 however, no matter how tight or loose I put them on, barely make much vapor at all, even on a PT, and seem a little harder to draw.
Maybe these "premium" cartos they are getting in have been made better by a better company, might have to buy a couple packs on next order.