I had ordered a bunch of bullets on Monday, received an email confirmation shortly thereafter, but received a follow-up email the next day (Tuesday) indicating they were low or out of stock on certain items I had ordered and my ordered was adjusted accordingly.
Their website is not updated live for stock, so it is possible to order items or quantities that they may not have in, or sufficient, stock.
At least they charged and shipped what they could rather than cancel my order. It ended up being about 1/4 of what I ordered though.