Shooting animation playing for longer than a second?

I have a shooting animation for my player that starts when the player presses "W" but it only lasts for less than a second. I'd like it to last until the animation is completed. Here is my script:

 using UnityEngine;
 using System.Collections;
 
 public class shootanm : MonoBehaviour {
     protected Animator animator;
     // Use this for initialization
     void Start () {
             animator = GetComponent<Animator>();
     }
     
     // Update is called once per frame
     void Update () {
         if (Input.GetKeyDown (KeyCode.W)) {
                         animator.SetBool ("w", true);
                 }
         else {
             animator.SetBool ("w", false);
                 }
     }
 }