A new version of Ballistic Explorer usually posts in January and that was true for 2017. The new version adds 50 some Lapua custom drag models and a drag analyzer that plots drag over velocity. I've played with such graphs on my own in Excel, but my efforts were crude by comparison. Here's an image I posted on another forum.

[Linked Image]

I don't know the specific rules, but I've been getting free updates since about 2005. I just check Web Updates in the Ballistic Explorer help menu and follow the links if there's an update.