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 ??

Cutting is the same as breaching in your example. I didn't calculate it myself.

But, for bigger holes, the surface you need to destroy, or to go through is smaller if you use cutting. The logic is that the surface and its surrounding don't have the same mathematical evolution. If you cut a piece of 10 m² or blow it, it's different...

On one hand, make a hole of 10 m², on the other one, make a line of 14 m explode...

That's how physics work in the real life in my understanding, now, for SR4, as you might know, reality is different...