Need help figuring how much explosive is needed to make a hole using Arsenal advance demolition rules. I also need help figuring out how Cutting saves explosives.

Stats:

- Heavy Structure (armor 16, structure 13), ie need a final DV 17 to make the hole.

- Need a hole 0.5m x 0.5m (Radius is 0.25m)

- The explosives will be untamped (to keep simple)

- Will be using explosive rating 4

Arsenal p.92, Calculating the Charge:

- DV required = (Rad x structure rating) + (Armor Rating / 4)

- DV required = (0.25m x 13) + (16 / 4) = 7.25 (rounding up to

- Explosive weight = (DV / DV Multiplier / Explosive Rating)sq

- Explosive weight = (8 / 1 / 4)sq = 4KG

Cutting p.93 (will be using the same explosive weight, ie 4KG)

- Need 2m of cut (0.5m x 4 sides)

- Demolition test to place the charge is (4, 5 min)

- Any extra hits becomes AP

- DV required = root(KG) x Explosive Rating

- DV required = root(4) x 4 = DV 8

If I understand Cutting, I would need to generate 13 hits on the Demolition test (to make -9 AP) so that Cutting becomes the same as simple breaching. Am I missing anything ??