発射された弓矢の所有者を設定できない

command /shotgun:
 trigger:
  set {damageProjectile.%player%} to 5
  set {_x} to x-coordinate of target block of player +1
  set {_y} to y-coordinate of target block of player +1
  set {_z} to z-coordinate of target block of player +1
  set {_v} to vector from location of player to location({_x},{_y},{_z})
  set vector length of {_v} to 0.8
  shoot an arrow from location of player {_v}
  set {_loc} to location of block above player