Don't worry about ammo, this only affects the plant that built certain models of rifle and shotgun. It's USRAC that's closing, and they're just some factory that bought the rights to stamp "Winchester" on the rifles they build.
A lot of these good ol' American companies are just some guys who plunked down cash for the legal right to use a famous brand-name. Not saying that the rifles that Armalite, USRAC, and others produce are necessarily bad, just that it's a bit odd that folks get all misty-eyed about the name when there's zero connection between the original business and the current one.
So yes, there are downsides in that the Model 70 and 94 won't be coming onto the shelves (until someone buys the name again, gets Miroku of Japan to build more outstanding Winchester copies at high prices, and legally stamps "Winchester" on them), but the Winchester company that makes ammo is a totally separate entity.
Not to bust your brass, but it would make things a lot easier to run a Search before asking this question, as it's been covered extensively on the board this week, and also to put in a clearer title, like "How will Winchester closing effect ammo prices", instead of the equivalent of "Hey you guys!". That way the folks with the best info will immediately arrive to answer your question, as opposed to people like me who are just procrastinating and willing to look at a thread which gives no indication of its content.
Not knocking you personally, tons of folks do both those things. But the more we all run a Search first and use clear titles, the smoother the board will run.
Take care,
-MV
(EDIT: TheDrew beat me to the punch while I was typing)