[Difference in dimensions between Hornady OAL gauge and my DIY measurem]

I have been struggling also to obtain reliable measurements for OAL in my 30-06. Please explain in more detail what you are doing with the dowel. Thanks

[Questions about pro chrono digital]

Looking to gauge the market need to an iPhone/Android app that will communicate via Bluetooth to a chronograph. I just purchased a Prochrono last weekend and immediately found the need for this. I know they make a wired USB to serial cable for it along with some software, but I am thinking about a wireless solution using a phone or tablet so you don't have to lug a laptop around.

I would like to know what people would value a full-featured software app at. $1, $5, $20? What about the Bluetooth hardware for the chronograph?

Ideally I would make the app function with the most popular chronographs. All opinions, gripes, desired features, etc. are welcomed. Looking for honest feedback here. Thanks.