gundrilling, and old ME articles sought

The original article was interesting in that it describes the experiences of an apprentice at BSA.  The basic production gun-drill consists of a drill face (usually a diamond shape) which has one or two small holes in it.  This is set into a hollow ‘V’ shaped tube.  The hollow part contains oil (under pressure – between 200 to over 1000 psi-).  The oil squirts out of the small holes and drives the swaff up the ‘V’ grove.  The rest of the system is an oil pump a ‘catcher’ which gathers up oil and swaff mixture, a separator to separate oil and swaff and recycles the oil. Nuff said.  You can do the job by using progressively longer series of drills and Peck drilling.  I use ‘pecks’ of the same length as the diameter of the drill.  Try drilling a 4” long 0.075” diameter hole down the barrel of a 1/10 scale musket. –Eek!

Your best bet is to do what Myford probably do, search the internet for a thick walled tube.  It is much easier and will cause you much less perspiration and cost.  The cost of a very long series drill is astronomic.  You can make them but that is another tale.

David,

The problem is in the tool’s name. It uses a word which causes All forms of ‘Authorities’, local Safety Managers, the local police, other long noses, who have no business to stuff their oars in but do so, to have the heeby-jeebys and act. This causes problems which will cost the ‘victim’ a lot of worry, heartache, loss of freedom and expense. In the eyes of these folk, for an ordinary citizen to have any knowledge of these things, or even things which are sharp, should be totally forbidden and those who have such knowledge be locked away. One very prestigious museum I know of had to remove all its extensive collection of very old examples of these things from public view. You can only see them by appointment and then only after, I understand quite extensive police checks.

I would suggest that the forbidden name and its associated names (which are also not to be mentioned) are not to be used.  The tool should be re-named as an “Extra deep hole making device”.  We are Model Makers, Engineers or Artificers we are not lawyers so it is best to steer well clear of such things altogether.

Finally it is not illegal to make any form of thing that looks like the ‘thing we must not mention’ so long as it cannot give fire or be EASILY converted to do so. You try telling them that! they will throw away the key.