Every once in awhile when I sneak up on someone and melee them to get the extra points, it takes more than one hit, is this because of the gun i'm using? Or is it because of where i'm hitting? Or just the game's collision detection?
It is probably the melee damage amounts:
- Melee to the head does 100 points of damage.
- Melee to the body does 50. Therefore two body hits are needed if the player starts at full health.
So yes, your targeting does affect the melee in SW Battlefront 2015, unlike most other games. This is also never communicated to you by DICE in any documentation or in-game tutorials or tips.
(Keep in mind, mediocre netcode settings that DICE uses also mean sometimes the melee just misses when it appears like it shouldn't, or vice versa for the opponent. Not much you can do about that since they lock down all the settings unlike most other good games, for example games based on Valve's Source engine. But if you have a decent, stable internet connection, this doesn't happen too often. If it takes a second hit, the first was most likely a body shot.)
However, why you are dying in melee battles might be other issues. ;-) If you sneak up behind them as you say, hopefully you should be able to hit them twice before they notice you unless you do something else to give yourself away, or they have buddies, etc.