If you're a user of my ballistic_PRS spreadsheet please make sure to be using version 1.7 or higher (1.7 is current as of this writing). The 1.5 version had a bug in the full metric setup that caused null values for all data for some users. This has been fixed. Also note that the Muzzle Velocity Variation table is non-functional in the PRS version since using Density Altitude means I can't confidently establish the air temperature. The MVV table is informational only in ballistic_PRS. http://ballisticxlr.com to download for free the updated version.