Modifying an older Corbin for pick resistance

[supercat101]

If all of the pins were lifted to a -1 depth (comb attack), the first 5 chambers would be lined up to the master ring shear line. The only thing preventing it from turning at that point is the 6th pin, which gets set to the shear line after the plug rotates 20ish degrees. However since that is the only pin preventing it from turning, the lock could theoretically be rapped on to bounce that pin.

I assume by -1 you mean below the minimum "legal" cut depth but above the warding? I see no reason you couldn't use pins which are long enough that the only way to line up the outer shear line would be to raise the key pin to the proper height.

As for the extra pin, as I posted on another thread my inclination would be to bit that for a height below the warding, and cam a surface on the inner plug to allow the pin to drop below the warding height. Bumping to let the outer plug rotate without having first rotated the inner plug to disconnect its chambers would be useless, since that extra pin would have nowhere to go.

[supercat101]

I assume by -1 you mean below the minimum "legal" cut depth but above the warding? I see no reason you couldn't use pins which are long enough that the only way to line up the outer shear line would be to raise the key pin to the proper height

Never mind--I reread your post and the issue is over-lifting. I would think for that your described fix would be simple. For all pins, regardless of bitting, limit the maximum travel to that of a maximum-height key.