I forgot to mention, for emphasis, that I would not use core, I would use RC for discovery drilling on a target like HM(porphyry/skarn). If it were a narrow vein target (like a high grade gold vein), RC drilling is certainly not the way to go since you can drill right through a vein and barely notice it in the chips. And with five-foot runs, your resulting assay from the run where the vein is, will be diluted out.