Here is a question that I am having a hard time figuring out. I purchased some 300 grain federal cast core .44 mag ammo for protection from mean critters while hiking etc. I looked at the factory ballistics on the box and it was around 1016 fps and 896 ft/lbs at the muzzle. I recently went to the range and got some Remington UMC 180 grain JSPs and those are rated over 1000 ft/lbs at the muzzle. How is it that there is less energy with a projectile backed by almost twice the powder? Is it simply that the hard cast lead is heavier? Lastly, is that the metric I should be looking at when determining the type of ammo to take into the woods? I know I don't want hollow points but rather penetration power, but it seems if energy is what's important the Remingtons would be the better choice (and at a fraction of the cost!) Thanks!