How Many Foguete de Alta Velocidade for Porta de Chapa de Metal?

11 Foguete de Alta Velocidade to destroy Porta de Chapa de Metal from the hard side — that's 2,200 sulfur once you count the full gunpowder chain. From the soft side (inside face) it's 8, because the interior takes more damage per hit

You need 11 Foguete de Alta Velocidade to break Porta de Chapa de Metal from the hard side — 'how much' and 'how many' come out to the same number.

The soft side is the interior-facing face — the side you see from inside the base. It takes roughly 34% less to break, so 8 Foguete de Alta Velocidade instead of 11. If you can get an angle on the inside face through a doorway or window, take it. On a wall, the soft side is the one without the visible seams.

No. Explosive 5.56 Ammo is cheaper on sulfur for this target — 63× costs 1,575 sulfur versus 2,200 for 11 Foguete de Alta Velocidade. That said, cheapest isn't always right: Foguete de Alta Velocidade may be faster to place or already in your base, and sulfur you've already farmed is a sunk cost.

2,200 sulfur, plus 3,300 charcoal. That's the full craft cost including the gunpowder each Foguete de Alta Velocidade needs, not just the final recipe.

About 2m 12s of placement time for 11 — that's the deploy time, not the farming. The farming is the real cost, and it's why people check this number before they commit.