Each bullet has 2 instance variables which i use to calulate the decline.
"bullet.traveldistance" = how many pixels the bullet will travel before it's destroyed.
"bullet.offset" = They Y offset of of the sprite following the bullet, based on the distances between the player and the traveldistance instance variable.
When the bullet is created the offset is '-40' ... when the bullet reaches the endpoint the offset value is '0'
So somewhere inbetween here i need to do some adjustments to the offset in order to get an arc.