Over here where I live the Montana Extreme products have came in the aluminum bottles for quite some time and although they look cool they leak like heck in your range box, so I have been using tipton and Sinclair bottles, they don't leak and a 20 oz bottle last me about a week so I doubt I loose much of it's potency, once put in the range box sun light doesn't get in and since the bottle doesn't leak like the aluminum ones do neither does any air. Sun light and air is what kills it so I believe I am safe, if you store yours in the window sill or out where the sun light can get to it then I agree with others to store it in the original container or dark glass bottle, mine comes from the factory and is through my barrel before the label is completely dry

but for you that don't shoot much maybe plastic isn't the way to go.
Wayne.