Results of a simulation study of the L3Harris CWM75KW industrial strapped magnetron is presented. This study is part of a larger project which studies the feasibility of achieving phase control and faster startup in the magnetron via controlled electron injection by using gated field emission arrays (GFEAs). The device was simulated by using the 3-D PIC code VSim at its typical operating conditions (18kV, 5A, 1900G, 896-929MHz). The startup behavior was examined with 1) no priming of any kind, 2) RF Priming, and 3) cathode modulation. With no priming, no oscillations were seen up to 300 ns; with RF priming for the first 50 ns, oscillations were then observed at 150 ns; and with cathode modulation to create electron spokes, RF oscillation was observed at 130 ns.