I, too, wondered if you had the correct tubes. But, of course, if the tubes were wrong, you would haver trouble with the hardware and the bushings fitting properly.
It just so happens that I have information in my <u>Pen Reference Chart</u> for that kit. The information I have been given indicates that the lower tube is 0.40" in diameter and the upper barrel is 0.481" in diameter. The current CSUSA recommendation for drilling the upper blank is to use a 12.5mm bit which is 0.491" in diameter and 0.011" larger than the tube. A 1/2" bit would be 0.019" oversize and probably a little too loose for most people to be comfortable with.
The CSUSA recommended bit for drilling the lower tube is a 27/64" bit which is 0.4219" in diameter and 0.219" over the tube diameter and again looser than most folks would be comfortable with. This problem has been discussed before and recommendations from folks who have built these kits is to use a 13/32" bit which is 0.4063" in diameter and 0.0063" over the tube size.
I don't have a lot of data accumulated yet; but it seems like most drill bit recommendations range from 0.006" over to 0.011" over. If you have a caliper, the thing to do is to measure your tubes and then measure your drill bits. Failing that, you can drill holes in scrap wood and find the bit that best fits the tube. One thing you should be aware of is that drill bits may not always drill holes of the diameter marked on the bit. There are many reasons that this is possible; but that discussion is beyond the scope of this message.
To specifically answer your question, yes there are problems with the bit recommendations for the Jr. Gent kit. As mentioned in an earlier post, there have been a number of instances, recently, of bit recommendations from manufacturers that were less than ideal for other kits as well.
To repeat an earlier comment, it is always a good idea to check with a caliper or test hole or both to save yourself any grief. You never know when you are going to get a bad tube, bushing, piece of hardware or drill bit. taking a few seconds to check everything in advance could save you the annoyance of spending time on a pen and finding out after the fact that there is a problem.
]
