ORIGINAL: npaden
Actually energy = velocity X mass. So a small bullet moving very fast would have more "inertia" as you put it, than a larger bullet moving slowly.
Like several others have already said though, there is almost no way to accurately predict what is going to happen when a bullet hits a twig, rock, etc. It could go right through ordeflect off at a 30 degree angle, regardless of the size or speed.
my statement was assuming both projectiles were traveling at the same velocity.
I believe you are referring to momentum when you say inertia, but if you are referring to energy as force, it ismass x accelleration(sp?), not mass times velocity.