Bottlecap Mine hint
This is a schematic weapon built from the following; a lunchbox, a cherry bomb, a sensor module and ten bottle caps. The schematics are obtained from Moira in Megaton, Knick-Knack in Little Lamplight, Herbert Dashwood's sale in Tenpenny Tower, and Jocko's Pop & Gas Stop. Every schematic increases the number of mines created per set of materials, up to a maximum of three. Its damage is 501.