Ammo "energy" is measured in ft/lbs on the box.
However, energy = mass * velocity^2.
Torque is often referenced as ft/lbs.
What is the difference between Torque and Energy? Why is ammo presented incorrectly?
Ammo is not presented incorrectly. Energy is also force * distance. In this case, the distance is not a lever arm like torque! The distance is the how far the force pushed a mass. If you exert 1lb of force on a block, and move it 1 ft across the ground... then you transferred 1lb-ft of energy. In this example the energy was dissipated by the friction of the ground.
Torque is force perpendicular to the lever arm. Torque units can be more clearly expressed by using a perpendicular sign between the force and the distance, i.e. lbs_|_ft or N_|_m.
Most technical papers use the short hand N_m for torque.
Its confusing because we don't use the metric system. Force, mass, torque, and energy are all very confusing in the english system because they were in use before modern definitions were established and so they blur the old definitions with the modern.
Metric...
measures of Energy: joules, kilo joules, kilo watt - hour
measures of torque: Nm