Very Strange Damage Modifiers?

I cannot tell if this is a bug or something I might have done with procedures (even though I have checked through them and none seem to look like they are doing something), but damage modifiers with different tools and different mobs seem to be really jumbled up and weird. It is hard to explain but hopefully this video shows enough. I will also show my procedures if needed.

https://www.youtube.com/watch?v=hufb3pufbmo&feature=youtu.be

-I cant kill entities without a ranged weapon like a bow

-A ranged weapon with a melee damage set to it DOES kill entities

-I can instant kill undead enemies