Bump Key for "hole" type Keys?

It seems quite feasible in theory, but in practice it would be far more complicated to make a 'dimple' bump key, than an ordinary bump key. Would seem to require a precision drill press with moveable work table adjusted by x and y micrometer screws. You would also need to calculate where to drill. Each pin position would need two adjacent full depth holes, the former set for when the key is not fully inserted and the fatter set for when it is fully inserted. The 'web' between the holes would force the pins on their upward journey.
Possibly a specially adapted dimple key cutter would also do the job.
This would probably rule out 90% of people who may be inclined to make a dimple bump key, but it would seem that if someone is highly motivated to make a bump key (eg private detectives on high value assignments, CIA, etc), a dimple key lock wold be inferior to Medeco, Abloy etc.
IMO if someone is very concerned about illicit entry without trace (law offices, journalists, owner, etc) Medeco seems the best bet and would be excellent value for money considering what could be at stake.

g'day

Agreed. That Dutch based crowd would be in the 'top 10%' I mentioned.
Have not heard any more from that guy who was trying to portray KABA cylinders (by implication the plain dimple type) as bump proof on this ng a little while back.

Youtube shows a video on how to open these locks .