The resurgence in popularity of subsonic .30 caliber bullets in 300 Whisper and 300 Blackout has led to the development of bullets that will expand at subsonic velocities. The availability of these bullets has led to questions about the applicability of this caliber for wildlife damage management. We conducted a preliminary investigation to determine the potential of subsonic .30 caliber bullets to quickly incapacitate medium-sized game animals, such as white-tailed deer (Odocoileus virginianus) and feral swine (Sus scrofa). We tested several bullets, including Lehigh Defense Maximum Expansion (LDME) bullets, reported to expand at 878 ft/s (268 m/s), using ballistic gel and calculating retarding forces and kinetic energy. The retarding force, effects on the ballistic gel, and kinetic energy was similar to those seen in 9 mm hollow point bullets. Based on this initial analysis, .30 caliber bullets fired at subsonic velocities are unlikely to instantly or near-instantly incapacitate a medium sized game-animal unless the central nervous system or heart is directly struck. Additional research should be conducted to further characterize the effectiveness of these bullets and for the potential of subsonic .30 caliber bullets to be used for wildlife damage management