[guncrank]

Nickel plate
You need a long 9 mm drill bit. You can make them by silver brazing or welding on drill rod extension.

I do use a lathe but other than that just regular jobber drill bits and aircraft extension bits.

I have drill out .22, .32 and 9 mm barrel with this way.

And if you use a drill motor, clamp the barrel so it does not move and drill half way then drill out other half.