Just a FYI, I believe Armbrust is the only one who will test factory loads.

This is the last contact infro I have for Tom Armbrust, but I would call first - 815-451-6649
1108 W. May Ave, McHenry, IL 60051

https://www.precisionreloading.com/view.php?pg=shot_proof

Scroll down to the bottom on the left "Ballistic Testing"
http://www.downrangemfg.com/index.php?option=com_content&view=article&id=54&Itemid=62

You can't use the USPS for live loads