Some results of experiments on developing metal vapor lasers with the longitudinal pumping by runaway electron beams (REB) are presented. The problems of the REB propagation through a long and narrow laser tube are studied. An optimal version of a magnetic system arrangement capable of superposing several REB's into a single narrow beam and guiding it along a laser tube axis with a high overall efficiency is proposed. Laser tubes are designed and laser emission has been observed in Cd and Zn vapors pumped by the REB. The data obtained can make a basis for developing and constructing lasers on vapors of other chemical elements as well.