How do I make a gun shoot multiple bullets like a machine gun if you press a key?

using System;
using System.Collections.Generic;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Windows.Forms;

namespace WindowsFormsApp1
{
    public partial class Form1 : Form
    {
        private List<Bullet> Bullets;

        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            Bullets = new List<Bullet>();

            timerControls.Interval = 500;
            timerControls.Start();

            timerBullets.Interval = 100;
            timerBullets.Start();

        }

        private void timerBullets_Tick(object sender, EventArgs e)
        {
            // we'll process the bullets on it's own thread to keep the UI thread free for input
            System.Threading.Thread t = new System.Threading.Thread(new System.Threading.ThreadStart(ProcessBullets));
            t.Start();
        }

        private void ProcessBullets()
        {
            // update all bullets
            foreach (var b in Bullets)
            {
                b.Update();
            }

            var deadBullets = Bullets.Where(b => b.Destroy).ToList();
            if (deadBullets.Count == 0)
            {
                return;
            }

            // We use Invoke to run the code on the same thread that created the bullet
            deadBullets.First().BulletUI.Invoke((MethodInvoker)delegate { deadBullets.ForEach(b => this.Controls.Remove(b.BulletUI)); });
            Bullets.RemoveAll(b => b.Destroy);
        }

        private void timerControls_Tick(object sender, EventArgs e)
        {
            System.Diagnostics.Debug.WriteLine(System.Threading.Thread.CurrentThread.GetHashCode());
            Bullet b = new Bullet();
            // hard-coded position, this will be the position of your gun
            b.Location = new Point(10, 200);
            b.Speed = 10;

            // I'm using a label to represent the bullet, you can use an image or anything else
            Label lbl = new Label { Text = "X", Left = b.Location.X, Top = b.Location.Y };
            b.BulletUI = lbl;
            this.Controls.Add(lbl);
            Bullets.Add(b);
        }
    }

    public class Bullet
    {
        public Point Location { get; set; }
        public Label BulletUI { get; set; }
        public DateTime Created { get; set; }
        public int Speed { get; set; }
        public bool Destroy { get; private set; }

        public Bullet()
        {
            Created = DateTime.Now;
        }

        public void Update()
        {
            Location = new Point(Location.X, Location.Y - Speed);

            if (Location.Y <= 0 || (DateTime.Now - Created).TotalMilliseconds >= 5000)
            {
                Destroy = true;
                return;
            }

            // We use Invoke to run the code on the same thread that created the bullet
            BulletUI.Invoke((MethodInvoker)delegate { BulletUI.Left = Location.X; BulletUI.Top = Location.Y; });
        }
    }
}