Ballistics question -- same powder charge different bullet weight

[bushmaster1313]

In general, if everything else stays the same, how much more or less energy is delivered to the target?

For example, I am thinking .44 Spl, which happens to be on my mind. With the same powder charge out of the same gun, lighter bullet (say 200 gr.) will be going faster than a heavier bullet (say 240 gr,), but which projectile will be packing more oomph -- the lighter bullet going faster or the hevier bullet going slower.

Thank you in advance.

 

[OKFC05]

Can't find "oomph" in my ballistics program, but if we use "POWER FACTOR", which is commonly used in action pistol competitions like IDPA and USPSA, I can give you a direct and authoritative answer:
You are going to have to add considerable powder to the light bullet to keep the same power factor (momentum in odd units) if you are going to keep the product of MV X bullet weight constant.
It is much easier to achieve a high power factor with a heavy bullet at moderate speed than a light bullet at high speed.

 

[bushmaster1313]

You are going to have to add considerable powder to the light bullet to keep the same power factor (momentum in odd units) if you are going to keep the product of MV X bullet weight constant.

It is much easier to achieve a high power factor with a heavy bullet at moderate speed than a light bullet at high speed.

Thanks,

So to look at it a different way, starting with a fixed amount of powder and a lighter bullet, when the bullet weight goes up the velocity goes down, but by a lesser percent compared to the increase in mass, so the result is a net increase in power factor.

So my next question, why does it seem to me that ammo for higher lethality is lighter bullets going at fast speeds?

 

[OKFC05]

Well, you have really jumped the fence and headed off on another trail.
Suggest a good read on momentum, energy, penetration, and "killing power." They aren't the same and "killing power" is not an objective measurement universally defined. Some worship at the alter of ME, but that isn't the whole story. Here's a calculator and some reading to get you started:
Energy Calculator


My .270 rifle is generally considered to be much more lethal than my 9mm pistol with similar weight 125 gr bullets, but there is a huge difference between the 5 grains of powder in the 9mm and the 60 grains of powder in the .270, and the .270 bullet is nearly 3 times as fast.

 

[reddog81]

Depending on how you define oomph will determine your answer.

Given your criteria the difference will be realativly small and probably not make a difference.