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Ballistic Calculator 2

User guide — a free, open-source ballistic calculator for Windows, Linux and macOS

Ammunition library and presets

Goal of this article: stop re-typing. Three things can be saved and reused — loads, sights and barrels — and they work in three different ways.

What Where it lives How it is edited
Loads One .ammox file per load, anywhere (data/ammo by default) Load / Save on the Ammunition tab
Sight presets Entries in user-dictionaries.xml, beside the executable Tools → Edit Sights…
Barrel presets The same file Tools → Edit Barrels…

The ammunition library is a folder of files

There is no library window and no database: a saved load is a file, and the “library” is whichever folder you keep them in. The application defaults to data/ammo, where the shipped sample cartridges live.

Saving. Fill in the Ammunition tab and press Save. You get a .ammox file named after the load, holding everything on the tab: the three required numbers, the drag table, diameter and length, a reference to a .drg if you attached one, and the four descriptive fields.

Loading. Load accepts two formats:

Loading replaces the whole tab and nothing else; the conditions, rifle and zero stay as you had them.

Three things worth knowing about a folder-of-files library:

Sight presets

Tools → Edit Sights… edits the named sights that fill the Rifle tab’s dropdown. A list on the left, the selected entry’s fields on the right, Add, Delete and Reset beneath, and OK / Cancel.

Reset replaces the sight list with the presets the application ships with, leaving your barrels alone. It only changes what is on screen — nothing is written until OK, so Cancel undoes it.

Field What it does
Name What appears in the dropdown
Sight Height Above the bore, centre to centre
H Click / V Click Your turret’s click size, in whatever angular unit the turret is marked in
Default Zero Optional — and it writes itself into the Zero tab when the preset is chosen

That last field is the one to be careful with, in both directions: it is genuinely useful (most rifles have a habitual zero), and it silently overwrites the zero distance you may already have typed. If you build presets, decide deliberately whether each one carries a default zero.

Worth building one preset per rifle you actually shoot, rather than per scope model: the sight height depends on the mount, which is part of the rifle.

Barrel presets

Tools → Edit Barrels… is the same shape — including its own Reset, which restores the shipped barrels and leaves your sights alone — with two fields:

Field What it does
Name What appears in the dropdown
Twist Rate Distance for one full turn — 7 in, 200 mm
Direction Left or Right

Both matter: the rate scales spin drift, the direction decides which way it goes. See the twist.

One file, and an update cannot touch it

Both editors read and write the same file, and saving from either writes the whole thing — sights and barrels together. That file is user-dictionaries.xml, beside the executable, not the data/dictionaries.xml that ships with the application. Three consequences:

Updating the application covers this and the rest of what a release replaces.

Which dialog opens in which units

The two dictionary editors are standalone — they describe hardware, not a shot — so they open in the units of the last trajectory you created, remembered between sessions and imperial until you have created one. The Ammunition tab’s Load and Save, by contrast, belong to whichever trajectory window you are editing.

That is the same rule as everywhere else in the application, and it is described under imperial or metric.

Next

The manual’s remaining articles — hit probability and the reference part (units, file formats, what the model includes, troubleshooting) — are listed in all articles and still to be written.


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