There are multiple reasons for stores not carrying silver bullets.

1. Kentucky was the first state to make it illegal to sell silver bullets back after the original, "The Wolfman." They believed that there was a chance that people would take the fear to heart that there were werewolves, and that they should go hunt them. Other states began to accept this policy as well. It soon became a federal law.

2. Even if it was acceptable to carry silver bullets, most locations would not. The difference in price between a regular bullet adn a silver bullet would turn off a lot of buyers. Most gun shops try to stay away from novelty.

3. There are not very many stores that will carry true silver products. This adds a liability, and could also add to the insurance rate. Stores that would have definite jewelry counters that carry substantial amounts of jewelry have to hold specific insurance just for the counter. This can get expensive.

4. The silver bullets used in horror movies are pure silver. Pure silver is a pretty soft metal. A bullet made of pure silver would either explode upon hammer impact, or melt. Bullets are made of stronger metals to hold up long enough to travel out of the gun barrel, and over a long distance. This ends up being the second ultimate reasoning for the, "No silver bullet legislation."

I have a friend that is a werewolf freak, and also a gun fan. He told me that to make a, "safe," silver bullet, it would have to be at least a 80/20 mixture (probably 20% lead) with a strong variable metal. Other than that, you would raise the concerns for danger.

It is legal, though, to sell sivler bullets online, or in a novelty capacity through a mail order. Most of these will have a nickle plating over the caseing to keep it reinforced. Creting it like this, lowers the melting quality that can happen at higher caliburs. Since the silver would not be melting, it's weight and lower density actually cause it to hold it's shape after impact.

Stragnely enough, most people do not know the fact that silver bullets were invented by Hollywood as a way to destroy a werewolf. Silver bullets, the full moon transformation, and aversion from silver are all creations of Hollywood. One of the most common ways to kill a werewolf was to drive a stake through it's heart. Univesal Studios believed that this would turn viewers off since that was the same way to kill a vampire.

It's actually a government policy to not allow ANY commercial store to carry silver bullets. The government feels that by allowing stores to carry silver bullets, they are there in approving private citizens for the hunting and capturing of lycanthropic citizens. Since there is already a splinter group of supernatural hunters that has forms from militias and big game hunters, they feel the availability of silver bullets and other 'silvered' munitions will only exasperate the situation.
Don't fret though, there is a solution to keeping your how safe in the event of a werewolf invasion:
http://hurog.com/books/silver/silverbullets.shtml

This site will take you through the ups and downs of casting your own silver munitions.

That's because the Werefolf Lobby has already gotten their fingers into Walmart executive circles. Walmart has a pro Wolfman policy.

http://t2.gstatic.com/images?q=tbn:_4ruFaGlV3LmSM:http://i77.photobucket.com/albums/j68/juliagaudette/teenwolf_l.jpg

I have actually seen a silver bullet but it was on a chain around someone's neck, lol. Of course, this was not anything suitable for actual use in a firearm but it was great idea for a necklace charm.

Your question gave me a laugh when I saw it. Thanks for that!

This site even has white gold, diamond encrusted, hollow point bullets. OOo... I would like one of those!!

I think it's mostly for economic reasons. There aren't that many werewolf hunters and most make their own silver bullets, so there's not a great demand. With the lack of potential buyers and the price of precious metals, Walmart just can't sell them at the discount prices that are the foundation of their business model.