Dave Liquorice wrote:
On Sat, 15 May 2004 20:10:39 GMT, Cicero wrote:

Have you considered a wood auger bit? They come in quite large sizes
but even the large sizes have a small shank (about 9mm).

As the OP wants joined holes I think an auger bit is the only sensible
approach. Any "ordinary" drill is just going to wander into the
adjacent hole very quickly. Even so I doubt an auger bit will keep
true for 1/2 a meter...

It won't.
If you can get a long enough drill, it reduces to more or less making
it swiss cheese, then hitting it with a sledgehammer/drift, and picking
bits out.