My bullets won't bounce in Unity?

I wanted bullets to bounce when they hit walls. However when colliding with a wall, they just jitter about on them. I didn’t want to create a new physics material as I want to keep the ball moving at a constant speed and to have them destroy themselves after they have bounced once. Thus, I wrote everything in Code.

The constraints for the bullet rigidbody’s freezing position is the Y axis while the freezing rotation is X, Y, and Z axis.

I also wondered if the initial position the instantiated bullet also had something to do with the speed the bullet travels:

GameObject bulletObject = Instantiate(bulletPrefab);
bulletObject.transform.position = transform.position + (transform.forward * -1);

Here’s the minimum reproducible code:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class bulletMovement : MonoBehaviour
{
    private Rigidbody bulletRB;
    private Vector3 lastVelocity, initialVelocity;
    public float bulletSpeed = 10f;
    private int bounceCount;
    // Start is called before the first frame update
    private void Start()
    {
        bulletRB = GetComponent<Rigidbody>();
        bounceCount = 0;
        bulletRB.AddForce((transform.forward* -1) * bulletSpeed);
    }

    void Update()
    {
        lastVelocity = bulletRB.velocity;
    }

    // Update is called once per frame

    private void OnCollisionEnter(Collision col)
    {
        if (col.collider.tag == "Walls")
        {
            bounceCount += 1;
            if (bounceCount < 2)
            {   
                Bounce(col.contacts[0].normal);
            }
            else
            {
                Destroy(gameObject);
            }
        }
    }

    private void Bounce(Vector3 normal)
    {
        var speed = lastVelocity.magnitude;
        var direction = Vector3.Reflect(lastVelocity.normalized, normal);

        Debug.Log("Out Direction: " + direction);
        bulletRB.velocity = direction * Mathf.Max(speed, bulletSpeed);
    }
}

lastVelocity = bulletRB.velocity; is required to be in Update or else the bullet won’t move at all.