Which Kangers are you using and where did you get them? I myself had tried 2 Kanger cartos, from two different boxes and was unable to get them to make contact with the top brass. So they never fired. These cartos were bought about a year ago, so I am just wondering if something has changed with Kangers since then.
these came from myvaporstore.com, now they're outa stock (stainless at least). they are fickle, and the bottom of the carto has to be recessed just a little, but i get them to fire with a little extra torque. it's like they're the exact length of the tank, but all you need to make contact is just a tiny tiny little lip hangin out the top. once i get em set they're fine, no mis-fires or anything.
they come in a blister pack, just like 808 cartos. and, if i get to the point where i can't find regular, (just ordered 4 from good prophets, last 4 they had) i'll just get the xl, and cut them down. since they're horizontal coil i don't think there's anything running up the length of the carto. so you really could just cut them to size, pick out some excess filler so it's recessed, and pinch the center tube with some dikes as low as you can get it. i bet it be absolutely fine.
i was gonna get some stuff from ikenvape, but these are workin so well for me that i just said forget it.
i'm seeing a couple people are having probs with them, what i'm using measures 1 & 11/32" don't have a metric ruler, but i hope this helps.