You DONT want the tube to fit tight because you will not be able to get the tube out of the jig, the drill leave a small bur on each hole and if its tight you cant get it out, I found this out the hard way[:@] There should be some play between the tude and the jig and I used a small amount of masking tape to keep the tube centered, then drill one hole and I placed a tooth pick in that hole to keep the tube from turning in the jig. Once all the holes are drilled you will need to push the tube out of the jig with another tube the same diameter, a few taps with a hammer will push the tube out, then I put the tube in the drill press hand tight and sanded the bur off.

Ron