A projectile comprising a body having a channel, one or more recesses in the channel, a plunger in the channel, and a fluid in the channel is provided. When the projectile impacts a target, the plunger is driven down the channel, exerting a force on the fluid. The fluid, in turn, exerts fluidic pressure within the recesses, promoting rapid yet predictable expansion of the projectile. Another embodiment of the present invention provides a projectile utilizing a non-Newtonian fluid to optimize expansion of the projectile upon impacting a target.