This work focuses on optimizing drilling and blasting in advance work with 8x9 foot sections, in a type IIIB (Bieniawski) structural rock, in the Valeria I Zone. By replacing the burnt-cut drilling mesh by the perforation mesh with cylindrical cut, designed according to Holmberg's mathematical model. The methodology used in the investigation is of a descriptivecomparative type, the population is composed of the linear work of exploration and development progress, for the data collection the direct observation guide was used. The results obtained were very favorable, managing to increase the advance per shot from 1.89 to 2.08 meters, which represents a 9% increase in advance, going from 83% to 92% efficiency. Likewise, the reduction of drilling and blasting indicators was generated. Decreasing the linear load factor from 23.42 Kg/meter to 19.75 Kg/meter, the volumetric load factor was red...