The rumblings of a Sprint iPhone 5 have been growing louder as we've marched toward the device's rumored October arrival, and today we've got more evidence to support the claims that Hesse and Co. may soon be landing Apple's upcoming smartphone. A Best Buy document sent over to BGR shows that the retailer is expecting the iPhone 5 to come to Sprint and that the new handset could be launching in the first week of October. Additionally, it sounds like Best Buy may be planning to begin taking pre-orders for the iPhone 5 as soon as this week. The leaked doc also notes that, as usual, launch dates and product intros are always subject to change.

Keeping up with the iPhone 5 rumors, a separate Best Buy leak shows that the retailer has an "Apple Fixture Installation" scheduled for Friday, October 21st, and that managers will need to be at their stores at 6AM on that date. The source of this image says that it's not normal for a Best Buy manager to come in until 7 AM and that a similar scheduling was made when the iPhone 4 launched last year. Although this image doesn't call out the iPhone 5 by name, some feel that it could be an indicator that the handset could be arriving on October 21st. Best Buy Mobile managers are also prepping for a meeting on October 10th to “discuss upcoming BIG release dates,” claims the tipster.

So there are a couple of new potential iPhone 5 release dates to pencil in on your calendar. The rumor that the iPhone 5 will be launching in the first week of October lines up with previous claims that the device could be arriving early next month, although a recent report from the Wall Street Journal alleged that the new iPhone (including a Sprint version) is due in mid-October. Right now it looks like the iPhone 5 release date waters are still a bit murky, but we'll be sure to pass along more info when we get it to try and clear things up a bit.

Via BGR, This is my next