Ignore Colliders

Hello all, I am having a bit of an odd problem.

I am attempting to write a gun firing script, the problem is when the player fires the bullet hits their own ships collider. Heres the code:

Rigidbody instantiatedProjectile = Network.Instantiate ( bullet, firepoint.transform.position, transform.parent.rotation, 0 ) as Rigidbody; 
instantiatedProjectile.velocity = gameObject.transform.TransformDirection(  0,0, speed ) + gameObject.transform.parent.rigidbody.velocity; 
Physics.IgnoreCollision( instantiatedProjectile.collider, gameObject.transform.parent.collider, true );

This is attached to a gun object, which is a child of the players ship. Basically IgnoreCollision does not seem to be effecting the bullet. Any ideas why?

For anyone who has a similar problem here is what I did to solve it:

I attached this script to my bullet object:

public void AddCollider(Collider c1, Collider c2){
    Debug.Log("Ignoring " + c1 + " " + c2);
    Physics.IgnoreCollision( c1, c2, true );            

And then when I instantiated I did this:

boxcol = gameObject.transform.parent.GetComponent<BoxCollider>();
boxcol2 = instantiatedProjectile.GetComponent<BoxCollider>();
capsulecol = gameObject.transform.parent.GetComponent<CapsuleCollider>();
capsulecol2 = instantiatedProjectile.GetComponent<MeshCollider>();

bullethits = instantiatedProjectile.GetComponent<IgnoreHits>();
bullethits.AddCollider(boxcol, boxcol2);
bullethits.AddCollider(boxcol, capsulecol2);
bullethits.AddCollider(capsulecol, capsulecol2);

I have two explinations for why this may work when other attempts did not:

  1. Now I am assigning the IgnoreCollision in the bullet object instead of the gun object
  2. Both objects have 2 colliders, so I make sure they all ignore eachother