Don't throw scripts at people and expect them to know what to do with it.
Even I don't know what the forget to do with it.
Coding Help has a number of mottos and rules of thumb that vary from person to person.
Generally the majority try not to hand everything to you on a silver platter.
If you need a specific level of script you need to specifically ask for it.
Also you don't know what "the forget" to do with it because (I can only assume, and the assumption should be taken lightly at that) of your own incompetence.
Anyways, this is as close as I will touch this one right now.
if(getword(%pos, 2) > getword(%col.getWorldBoxCenter(), 2) - 3.3){
As I sit here I realize that I've never really tested this to see if it actually works(as in, it compiles but I've never extensively tested it in all my years), but that's my usual line of code for detecting headshots, given the projectile::oncollision. Is the projectile's position(Z of %pos) above a certain position on the player (Z of %col.getworldboxcenter())?
You could adapt this for feet, is it below a certain position. Getting arms would be difficult with this code but you could probably find a way.
Maybe you can adapt it or confirm/disprove it's effectiveness.
Look; I don't know whether or not this will help, but I think we can all agree that MtnDew isn't contributing in a useful manner.