Just to toss more confusion into your woes, perhaps you should find out how spokes mfgs measure their lengths. I know DT DOES NOT measure from center of the J-bent section to the tip of the threads. They use inside to tip length, so if you use 2mm, you should add 1mm. Sapim, on the other hand, DOES measure center to tip and their labeled lengths are exactly 1mm short when you lay it on a Park spoke ruler (what I used for the DT also).