In my seemingly never ending search for the best tank carto I tried a few Boge slotted XL cartos. Seemed to be great, so I ordered a bunch. Now, they mostly seem to function OK, but probably half of them have an extremely tight draw. They all look the same. The hole through the center all look the same. I think the issue might be that on the tight ones, the rubber insulator inside the threaded portion (between the outer threaded portion, and the center (positive) post protrudes up and is partially blocking the two air holes just under the threads. Clear as mud? Anyone else have this issue?