How can I rotate something welded to the player?

Code:

workspace.ChildAdded:Connect(function(obj)
    wait(1)
    if obj:FindFirstChild("Humanoid") then
        local gun = script.gun:Clone("Gun")
            gun.Parent = obj
        local weld = Instance.new("Weld")
        
        weld.Parent = gun
        weld.Part0 = gun
        weld.Part1 = obj:WaitForChild("Torso")
        
        weld.C0 = obj.Torso.CFrame + Vector3.new(0.6,0.4,0.6)
        weld.C1 = obj.Torso.CFrame

    gun.CFrame = gun.CFrame * CFrame.Angles(math.pi / 2, 0, 0)
    end
end)

Result: https://gyazo.com/bf7a240ac09dc69d0242af05f9b12462

Am I missing something obvious?

I'm new to CFrames. I just want the gun to be rotated so its facing down.

You could change the C0 or C1 properties of the weld to rotate and move the gun.

It might seem complicated but as far as i know it is one of the easiest methods there is.