The methane control and the respirable dust groups at the Twin Cities Mining Research Center (TCMRC) cooperated recently in obtaining production samples of approximately 1 ton each, from the loading conveyors of a ripper, a borer, and a loading machine in conventional development headings. These samples were sized, in four stages, from plus 4 in to minus 10 um. The conventional product had the least fines of the three production methods. The borer product had more fines than did the ripper product, but it also had a greater amount of large pieces. All three products, as sampled, had essentially the same amount of minus 10-um particles. Photomicrographs and surface-area comparisons were made. Gas- adsorption, surface-area determinations on particles under 37 um give essentially the same value. Surface-area calculations, assuming spherical particles and no porosity, give a smaller area to the conventional product.