The Maryland Centrifugal Experiment (MCX) and HyperV Technologies Corp. are collaborating on a series of experiments to test the use of a plasma gun to inject mass and momentum into a magnetic-confinement device. HyperV has designed, built and installed a prototype coaxial gun to drive rotation in MCX. The gun has been designed to avoid the blow-by instability via a combination of electrode shaping and a tailored plasma armature. Preliminary measurements at HyperV indicate the gun generates plasma jets with a mass of 160 mu g, velocities up to 90 km s(-1) and plasma density in the high 10(14) cm(-3). This paper emphasizes characteristics of the plasma gun and penetration of the plasma jet through the MCX magnetic field. Plans for future injection experiments are briefly discussed.