kappa-carbides of varying composition, seemingly responsible for age hardening in high-Al steel alloys, have been detected to precipitate both at grain boundaries and in the bulk grain of steels. Herein we report the bulk phase synthesis of "Mn3AlC" by arc plasma sintering and rapid solidification. Single crystals have been found suitable for X-ray diffraction using Mo radiation and yield a lattice parameter of a = 3.875(2) angstrom. We find a mixed occupation of the la position by Al and Mn, which, together with the C position being fully occupied, leads to the actual composition Mn3.1Al0.9C. Additional energy dispersive X-ray scanning electron microscopy measurements support the composition and corroborate the homogeneity. SQUID data collected on the polycrystalline ferromagnetic sample exhibit a Curie temperature of about 295 +/- 13 K and a soft magnetic behavior. The small but significant nonstoichiometry on la leads to a slightly larger lattice parameter, a higher electron count, and, thus, a lowered density of states at the Fermi level, indicative of increased phase stability.