The shooting mechanics

I finally finish my shooting thingy, but something's wrong when I try to shoot with some rotations.

I'm very new for Unity... So, u may expect me to be stupid.

When I shoot, the bullet seems ok, but in some direction, the bullet seems to hit the player. That means, in some directions, I hit myself with the bullet, and the bullet shoots in different direction but if I look at somewhere else, it works perfectly. So, here's the code for the bullet and the player:(btw, it's Javascript)

Player:

 #pragma strict
 var player : GameObject;
 var forward : float;
 var rotate_H : float;
 var rotate_V : float;
 var bullet : Rigidbody;
 function Start () {}
 
 function Update () {
  var move_forward = Input.GetAxis("Vertical") * 5;
 GetComponent.<Rigidbody>().AddRelativeForce
 (0, 0, move_forward * 10);
 
  rotate_H += Input.GetAxis("Mouse X") * 10;
  rotate_V -= Input.GetAxis("Mouse Y") * 10;
  if (rotate_V > 50) {rotate_V = 50;};
  if (rotate_V < -80) {rotate_V = -80;};
  transform.rotation = Quaternion.Euler(rotate_V, rotate_H, 0);
  
  if (Input.GetButtonDown("Fire1")) {
   var bullets = Instantiate(bullet, transform.position, transform.rotation);     
      bullets.velocity = transform.TransformDirection(Vector3(0,0,300));
 };
 }

Bullet:

 #pragma strict
  function OnCollisionEnter (col : Collision) {
      Destroy(gameObject,5);
  }
 

I plead for help, I need to finish the whole thing within a month-,-

(Here's the Thank for everyone who watches or replies. Thnx)