Chronograph data Pro

When you log a group, Pro users see three optional chronograph fields: average velocity, standard deviation, and extreme spread. Filling these in ties your velocity data to a specific load, session, and distance so it accumulates into recipe-level analytics over time.

The fields

All three fields are optional and live on the group form alongside distance and shot count:

• Avg Velocity (fps): the average velocity reading from your chronograph for that string. Accepted range is 100 to 5000 fps.
• Std Deviation: standard deviation in fps, entered as a decimal.
• Extreme Spread: the difference between the highest and lowest velocity in the string, in fps.

Recorded values appear on the group in the session detail view when Pro is active.

Where the data appears

On the recipe detail page, Loadatum aggregates velocity data across all groups logged for that recipe and shows average fps, average SD, and average ES. Only groups where you recorded velocity are included in the average. The more groups you tag with chronograph data, the more representative the picture becomes.

The firearm analytics page also tracks velocity consistency per gun across all loads shot through it.

The Analytics page Ammo tab includes a Velocity by Firearm chart (Pro). Select a batch or factory ammo load, then pick one or more firearms to plot that load's velocity over time for each gun side by side. Sessions with multiple groups are averaged into a single point.