yeah, I've used .010 mostly. (I've also piggybacked like a .006 on the existing stainless, and had some hit-or-miss luck with the .012.) The stock insulator is just a hair longer than it needs to be. The real touchy point of contact is in the center of the length of the pin where the delrin cover has a spine and pushes the pin body up dam close to where the aluminum shelf (the bottom side of the "510 cube" area) ends. When we push the button, the pin arches up in this central part. If your insulative sleeve is, say 2-3mm shorter than stock, that could be it. (or if it's damaged in that area) Also, of course, inserting the pin in the sleeve can cause a tear along the edge. That tear would have to migrate quite a bit to cause any trouble.