Put another coat of primer on the ends of the W-818 ends, then moved on to the W-816 tubes. I used the tube previously marked (yesterday) to mark the 6 holes on a piece of paper. Used the paper to wrap around the ends of W-818 and mark for drilling. Drilled all holes to 1/16”, then drilled them out to #40. Checked the fit of the end pieces that need to be inserted into the tube—extremely tight fit. Appears that once inserted, I won’t be able to remove them—will have to get them inserted to the proper depth on first attempt.