The blueprint is the cheap part: the same scrap and the same Level 2 bench as buckshot, so groups learn it on a whim. The shells are what cost. Each craft takes buckshot's whole recipe and then as much raw sulfur again as sits inside its gun powder.
That raw half is the trap. It never shows up in the powder queue, so nobody notices it leaving the box until the explosives craft stalls for want of raw sulfur. A full stack takes 1,280 sulfur, twice what buckshot asks. Load them where fire is the point, never for a straight duel.
Tip
Give incendiary shells their own small box and craft a handful at a time. Any even number leaves nothing over, and nobody empties the raid sulfur by accident.
Questions
12 Gauge Incendiary Shell ×10: how many resources?
Sulfur ×200, Charcoal ×150, Metal Fragments ×25.
Which workbench does 12 Gauge Incendiary Shell need?
Workbench level 2.
How long does 12 Gauge Incendiary Shell take to craft?
5 s for one, every step included.
How much scrap does researching 12 Gauge Incendiary Shell take?