Using the grazing incidence pumping technique with a 600 mJ, 500 ps background pulse and a 250 mJ, 200 fs main pulse the lasing emission from a molybdenum target has been studied. A flat field spectrometer designed to observe the X-ray laser emission in both the first and second orders was used to record the time integrated data. Time resolved data was obtained by installing an Axis-Photonique PX1 X-ray streak camera to observe the first order output from the spectrometer whilst retaining the time integrated second order observation. In this paper both time integrated and time resolved data are presented for a range of grazing angles, target lengths, delays between pumping pulses and pumping energy. Comparisons are also drawn with simulations from the Ehybrid and Medusa codes. An additional experiment is also described in which a two colour pumping method is used to investigate lasing at short wavelength from high Z targets (Z ≥ 62).