Why does my gun fire in full auto twice if I press down twice?

My username is Yeeterbo_i and I am a beginner scripter. Recently, I have been trying to make my own non raycast gun for future games. However, I just ran into a problem while trying to make it full auto. If I click twice before my gun fires again, my gun instead of going pew (wait 0.1) pew (wait 0.1) pew, it goes like this: pew pew (wait 0.1) pew pew (wait 0.1) pew pew.

If you need the script for my gun, its down here.

-- This is an extremely simple non-raycasting pistol made by Yeeterbo_i. It is basically a fancy damage brick teleporter.
--Variables
input_service = game:GetService("UserInputService")
local tool = script.Parent
local player = game:GetService("Players").LocalPlayer
local mouse = player:GetMouse()
local ammo = 12
local mag = 12
local CanReload = true
local reload = false
local Firing = false
tool.Equipped:Connect(function(mouse)
	

 mouse.Button1Down:Connect(function()
	Firing = true
	while ammo > 0 and reload == false and Firing == true  do --Checks for ammo and if player is currently reloading
	
		--Visual effects
		tool.FireDecalHolder.FireDecal1.Transparency = 0
		tool.FireDecalHolder.FireDecal2.Transparency = 0
		
	tool.SlideBack.Transparency = 0
		tool.Slide.Transparency = 1
		--Audio effect
		tool.FireSound.TimePosition = 0
		tool.FireSound.Playing = true
		
		--Creating damage brick
	local oof = game.Workspace.Oofpart:Clone()
		oof.BrickColor = BrickColor.Black()
		oof.Size = Vector3.new(0.7,0.7,0.7)
		oof.Position = mouse.Hit.p
		oof.Transparency = 0
		oof.Anchored = true
		oof.CanCollide = false
		oof.Parent = workspace
		
	game:GetService("Debris"):AddItem(oof, 0.001)--Removing block
	ammo = ammo - 1 --Removing ammo from mag
	wait(0.05)
	
	--Removing visual effects
	tool.FireDecalHolder.FireDecal1.Transparency = 1
		tool.FireDecalHolder.FireDecal2.Transparency = 1
		
	tool.SlideBack.Transparency = 1
		tool.Slide.Transparency = 0
		wait(0.1)--ROF
	end
if ammo < 1 then
	tool.EmptySound.TimePosition = 0
	tool.EmptySound.Playing = true
		end
	end)
end)
mouse.Button1Up:Connect(function()
	Firing = false
end)
 function PressedR(key)
    if key == "r" and CanReload == true then
	CanReload = false
	script.Parent.ReloadSound.Playing = true
        	print("oof")
		reload = true
		wait(1.5)
		reload = false
		ammo = mag
	CanReload = true
    end
end

mouse.KeyDown:Connect(PressedR)

It happens because every time you click with your mouse you set Firing to true and then in the next line you check if it's true which means it will be true every time you click.

Simple fix would just be to check if it's false.