How can you update ammo and clip in a gun gui?

I have number value objects under the main local script in the gun and I have successfully applied those values to the gui but how can I update them efficiently? A while loop won't work since I can't run the other code in the script. Should I use coroutine? Any answer is appreciated!

if clipleft.Value > 0 then
            fire()
            clipleft.Value = clipleft.Value - 1 -- how can I make this change in the gui as well?
        elseif clipleft == 0 then
            emptyclip = true
        else
            outofclips = true
        end