My bullet instantiates but will not move forward?

using UnityEngine;
using System.Collections;

public class Mover : MonoBehaviour
    public float speed;
    private Rigidbody rb;

    void start()
        rb = GetComponent<Rigidbody>();
        rb.velocity = Vector3.forward * speed;


this is my script for my bullet and it instantiates perfectly fine but will not move forward. I have set the speed in the inspector and am using a capsule collide for this instance. I have also tried using transform.forward instead of Vector3 but neither work.

check speed that is not zero
check your script and your gameobject bullet is active
check Start function is executed?