Advanced guide

Keeping a range logbook

The Logbook ties a range day together: what you shot, how fast it went, what the wind did, and which range card and group each string belongs to.

Recording sessions, shot strings, chronograph data and wind so every range day informs the next.

Sessions and strings

A session is one range day. Inside it are strings — each string is one set of shots fired under one set of conditions (a chronograph string, a group at a given distance, a load in a ladder test).

A logbook session for a Bisley range day with session details filled in and one shot string containing a linked range card, linked group analysis, a six-shot chronograph table and wind conditions. — Session details at the top; one string below with its linked card, linked group, chronograph data and wind.

Session fields

Date & Time	When you shot. Used to order sessions and stamp any group analyses you create from a string.
Location	Range name. Also used as the label for groups created from this session.
Conditions	Free text for the day — temperature, cloud, light, general wind picture.
Notes	Anything session-wide: rifle, load being tested, what you were trying to learn.

Inside a string

A single logbook string showing range, linked range card, linked group analysis with mini stats, a chronograph table with average, high, low, extreme spread and standard deviation, and wind speed and clock direction. — One string: chronograph readings with live Avg / High / Low / ES / SD, plus wind and linked data.

Range and linked data

Range — the distance for this string.
Range Card — link a saved card so you know exactly which dope this string was fired on. The velocity you record here is the ideal input for truing that card later.
Group Analysis — link an existing saved group, or hit New to open a quick group analysis pre-filled with this string’s calibre, range and date.

Chronograph

Add readings one at a time with Add Shot, or Import CSV to pull a whole string from most chronograph exports (it auto-detects the velocity column). Set the velocity unit to match your device. The stats update live:

Avg	Mean velocity — the figure to put into the calculator’s Muzzle Velocity field.
High / Low	Fastest and slowest shot in the string.
ES (Extreme Spread)	High minus Low. Simple, but driven entirely by the two extreme shots, so it grows as you add shots.
SD (Standard Deviation)	Sample (n−1) standard deviation of the string — the better measure of consistency. Lower is better; single digits (fps) is very good. High SD shows up as vertical dispersion at distance, so it caps your realistic long-range accuracy.

How many shots? SD needs a reasonable sample to mean anything — 5 is a minimum, 10 or more is meaningfully better. A “good SD” from a 3-shot string is mostly luck.

Wind

Record the wind speed, its unit, and its direction as a clock face relative to your line to the target:

12 o’clock	Straight headwind (blowing from the target toward you). Minimal horizontal effect.
3 o’clock	Full-value wind from your right, pushing impacts left.
6 o’clock	Straight tailwind from behind you.
9 o’clock	Full-value wind from your left, pushing impacts right.

Logging this next to the group means that when you review the session you can tell a wind call apart from a genuine zero shift.

Saving and sharing

Save names and stores the session in your browser; saved sessions appear in the dropdown at the top of the page.
Share creates a link containing the whole session — strings, chronograph data and all.
Sessions, cards and groups can also ride along with the app’s optional Google Drive sync and the backup/restore tools in Settings.

A practical loop

Build a range card from book data before the range day.
On the day, log a chronograph string and link it to that card.
Shoot groups at distance; capture each with group analysis and link them to their strings.
At home, put the measured Avg velocity into the card and true the BC against your recorded drops.
Next session, confirm the trued card — and log that too.