X-ray spectroscopy in the 12 to 15 A region of L-shell lines from selected transition elements was performed in a joint Naval Research Laboratory - KMS Fusion, Inc. experiment. The accurate wavelengths determined in this work will be utilized in selecting potential pumping candidates in future x-ray lasing schemes. Specifically, high-resolution x-ray spectra were collected under controlled geometric and target conditions using both red and green light laser excitation in the KMS Chroma laser. Three groups of x-ray spectra were collected with highly-dispersive x-ray crystals at wavelengths centered at 12.543, 13.781 and 14.458 A corresponding to He- and H-like lines from fluorine. Two specially-designed flat crystal spectrographs employing film shutters were used with pairs of beryl and TAP crystals. The spectra from potential lasant and pump candidates could be recorded on the same spectrogram to aid in identifying x-ray line coincidences. In cases where wavelengths were measured in both the red and green laser work, agreement within 1 to 3 mA was obtained for the L-series x-ray lines. Within this accuracy range, five L series x-ray lines, mostly 2p-3d transitions from the metals Cr, Mn, and Ni, had wavelength values coincident to K-series lines in fluorine.