I don`t know the speed of a 300gr JFP bullet from factory loaded 460 S&W ammo is but I do know if you double lung a boar at 50yds the results are impressive. The blood spray was a show in itself. The damage to the lungs was not a severe as what a hollow point would make but it was more then I what I`ve seen when shooting a JFP at 44 mag or hot 45 Colt velocities. Speed matters.....