Berkeley Mineral Resources, the company which aims to extract zinc and lead from residue dumps at the disused Kabwe mine in Zambia has begun re-drilling slag stockpiles.This phase of drilling is being carried out with the "percussion drills" necessary to provide samples that can be assessed by scientists. Previously auger drills were used which did not yield useable samples.In addition Berkeley has looked again at samples from deposits from the old washplant. These tests seem to imply there is a higher concentration of so called "JORC compliant" material within these dumps. The new test results show 7.21% lead and 10.66% zinc.This news saw Berkeley's share price rise 5.65% to 2.43p at 9.17am.BS