weapon sway rotation glitch

Unity Engine
1

below is my weapon sway script
works not as i expected. the problem is it overshoots when passing the “zero” of an axis.
how do i prevent this hickup in the rotation?
script:

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

public class gunsway : MonoBehaviour
{
    public Transform root;
    Vector3 rotationLast;
    Vector3 rotationDelta;
    public float rotationAmount = 4f;
    public float speed = 3f;
    public float x;
    public float y;


    void Start ()
    {
        rotationLast = root.transform.eulerAngles;

    }


    void LateUpdate ()
    {
        rotationDelta = (root.transform.eulerAngles - rotationLast)  / Time.deltaTime /200f;



        rotationDelta.y = Mathf.Round(rotationDelta.y);
        rotationDelta.x = Mathf.Round (rotationDelta.x);

        rotationDelta.x = Mathf.Clamp (rotationDelta.x, -4f, 4f) ;
        rotationDelta.y = Mathf.Clamp (rotationDelta.y, -4f, 4f);  

        Vector3 wantedrotation = new Vector3 (rotationDelta.x , rotationDelta.y,0f);
        wantedrotation *= rotationAmount;
        x = rotationDelta.x;
        y = rotationDelta.y;
        transform.localRotation = Quaternion.Slerp(transform.localRotation,Quaternion.Euler(wantedrotation),Time.deltaTime * speed );

        if (rotationDelta.magnitude == 0) {
            rotationLast = -rotationLast;
        }
        rotationLast = root.transform.eulerAngles;

        //transform.localEulerAngles = rotationDelta;
    }
    public Vector3 angularvelocity
    {
        get
        {
            return rotationDelta;


        }
    }


}
2

First thing: don’t use Euler angles. They’re awful and lead to an endless variety of glitches.

I suspect that will solve your problem. If it doesn’t, then post the Euler-free code and we can work on that. But without a doubt get rid of Euler. It’s either already causing problems or it will later.

3

theres nothing wrong with eulers
the problem is the same with quaternions. when getting to zero of an axis the weapon glitches