If you look at the bottom of the carto center pole piece (positive center circle) the round part inside the outer
thread wall. It has a straight indented line
through the middle of it , almost like a flat head screwdriver would be used to turn it. This is the valley that air flows thru when the carto is screwed down to your pv. If you put a Boge carto next to a smoketech,bottoms up, you can see the Boge has a deeper cut air flow "valley" the Smoketech has a more shallow valley. Reason why Boges have a more airy draw,more air can flow thru the deeper valley than a shallow one. I lay my dremel with a diamond edge 1/8th inch grinding spool all the way across the entire bottom of the carto and make a deeper valley from edge to edge,outer thread wall to outer thread wall,threads included. Heres a pic of the tip I use and the before and finished look of the carto after I do it. It literally takes 5 maybe 6 seconds to do this perfectly. Its toooo easy. The dremel I use cost me $9.83 at harbor freight tools,all the tips included,the tip I use to do this the dremel came with 4 of them and 80+ other tips and cut-off wheels and other stuff. This is also what I use to do my
tank carto holes.
BEFORE ................................................................AFTER
I hope this helps somebody out there.
This is what I used ::
You sounded pretty sincere to me.
