I am not exactly sure what you mean, but try this test. Hook up a piece of fuel tubing to the fuel intake nipple of the spraybar. With the needle all the way in(gently) can you blow air thru the fuel tubing. If not, then the needle is bottoming out in the seat, and you can probably needle the engine ok. If you can blow air, then something is wrong, and you may not be able to lean out the engine enough.
If it does stop air, then back off the needle. Hopefully it will now become possible to blow air thru the spraybar. I think the main issue with only 5 turns is that you probably won't have enough threads to hold the needl secure.
If you could blow thru with the needle all the way in, it is obviously being stopped by something. Either the threads don't go far enough in (I don't recall if the Veco Threads are internal in the spraybar), or there is something in the way. If the latter, I would take out the needle, and from the fuel nipple side, gently push in a thin needle (sewing variety type, to see if you can move whatever is in the way. Also look in the fuel spray hole. Maybe there is a burr there from the drillin operation.
Hope to be of some help, maybe not if I completely misunderstood the problem.
