weaponthrow.cs

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

public class WeaponThrow : MonoBehaviour {

	public Rigidbody rigidbody;

	void Update () {
		if (Input.GetKeyDown (KeyCode.Space)) {
			StartCoroutine(Throw(18.0f, 1.0f, Camera.main.transform.forward, 2.0f));
		}
	}

	IEnumerator Throw(float dist, float width, Vector3 direction, float time) {
		Vector3 pos = transform.position;
		float height = transform.position.y;
		Quaternion q = Quaternion.FromToRotation (Vector3.forward, direction);
		float timer = 0.0f;
		rigidbody.AddTorque (0.0f, 400.0f, 0.0f);
		while (timer < time) {
			float t = Mathf.PI * 2.0f * timer / time - Mathf.PI/2.0f;
			float x = width * Mathf.Cos(t);
			float z = dist * Mathf.Sin (t);
			Vector3 v = new Vector3(x,height,z+dist);
			rigidbody.MovePosition(pos + (q * v));
			timer += Time.deltaTime;
			yield return null;
		}

		rigidbody.angularVelocity = Vector3.zero;
		rigidbody.velocity = Vector3.zero;
		rigidbody.rotation = Quaternion.identity;
		rigidbody.MovePosition (pos);
	}
}

Will be tweaking this functionality