Why are my gun's raycast lasers at the wrong angle and sometimes not firing?

I'm pretty new to Roblox developing. I've been trying to make a raycast gun now, but when I click to fire the gun, the laser parts sometimes fire in the wrong direction. Sometimes, the laser part doesn't show up at all, even though a ray was fired. I think that the issue is with how I'm defining the parts' CFrame in the onShoot function, but I don't know what the problem is.

Local script

--Variables
local tool = script.Parent
local replicatedStorage = game:GetService("ReplicatedStorage")
local remotes = replicatedStorage:WaitForChild("Remotes")
local ammoStart = remotes:WaitForChild("AmmoStart")
local shoot = remotes:WaitForChild("Shoot")
local players = game:GetService("Players")
local mouse = players.LocalPlayer:GetMouse()

--When tool is equipped
tool.Equipped:Connect(function()
    ammoStart:FireServer()
    --When player clicks with tool
    mouse.Button1Down:Connect(function()
    local bulletStartPosition = tool.Handle.CFrame.p
    local bulletDestination = mouse.Hit.p
    shoot:FireServer(bulletStartPosition, bulletDestination)
    end)
end)

Server script

--Variables
local replicatedStorage = game:GetService("ReplicatedStorage")
local remotes = replicatedStorage:WaitForChild("Remotes")
local ammoStart = remotes:WaitForChild("AmmoStart")
local shoot = remotes:WaitForChild("Shoot")

--Making functions
local function ammoMaking(player) --Creates the ammo and clip for the player
    print(game.Workspace:FindFirstChild(player.Name))
    --Creates ammo
    local playerAmmo = Instance.new("NumberValue")
    playerAmmo.Name = player.Name.."'s Ammo Count"
    playerAmmo.Value = 10
    playerAmmo.Parent = game:GetService("ServerStorage")
    print(playerAmmo.Value)
    --Creates clip
    local playerClip = Instance.new("NumberValue")
    playerClip.Name = player.Name.."'s Clip"
    playerClip.Value = 4
    playerClip.Parent = game:GetService("ServerStorage")
    print(playerClip.Value)
end

--Executes when player attempts to shoot the gun
local function onShoot(player, bulletStartPosition, bulletDestination)
    local laser = Ray.new(bulletStartPosition, bulletDestination.unit * 500)
    local part, position = workspace:FindPartOnRay(laser, player.Character, false, true)
    local distance = (bulletStartPosition - position).magnitude
    local laserPart = Instance.new("Part")
    laserPart.BrickColor = BrickColor.new("Bright blue")
    laserPart.Material = "Neon"
    laserPart.Transparency = 0.25
    laserPart.Anchored = true
    laserPart.Locked = true
    laserPart.CanCollide = false
    laserPart.Size = Vector3.new(0.3, 0.3, distance)
    laserPart.CFrame = CFrame.new(bulletStartPosition, position) * CFrame.new(0, 0, -distance / 2)
    laserPart.Parent = game.Workspace
end

--When a player equips a gun
ammoStart.OnServerEvent:Connect(ammoMaking)
--When the player clicks with a gun in hand
shoot.OnServerEvent:Connect(onShoot)