Calibers

Your API key. Authorization: Bearer <key> is accepted in its place.

Caliber slug

Accepts

a lowercase slug: letters, digits and hyphens

Example

9x19mm-parabellum

The response payload

URL-safe slug identifying the cartridge, e.g. 9x19mm-parabellum.

Display name, as the maker writes it.

JSON array of aliases

NATO designation where the cartridge has one, e.g. 9mm NATO. Null otherwise.

Bullet diameter in millimetres.

Case neck outside diameter in millimetres.

Bottleneck cases only.

Case base diameter in millimetres, ahead of the extractor groove.

Rim diameter in millimetres.

Rim thickness in millimetres.

Case length in millimetres.

Overall length in millimetres, stock extended where it folds or collapses.

Typical projectile length.

Maximum average pressure in megapascals, as the standards body specifies it.

The same pressure in pounds per square inch, converted.

Representative bullet weight in grams. Divide by 0.0648 for grains.

Representative muzzle velocity in metres per second.

Representative muzzle energy in joules.

Primer size and type, e.g. small_pistol, large_rifle, rimfire.

Head type: rimmed, rimless, semi_rimmed, rebated_rim, belted, plus historical values like cap_and_ball. Not the broad class. The registry said pistol/rifle/shotgun until the column was read, and it holds neither.

Case profile: straight, bottleneck, tapered, belted.

What the case is made of: brass, steel, aluminium, polymer.

none is a blank.

Bullet shape: fmj, hollow_point, soft_point, spitzer, round_nose.

What seals the case mouth; a blank is a star crimp.

Paint that identifies the load: crimp lacquer on a blank, tip colour on a military round.

What that colour signifies, where the marking is a standard one.

The cartridge this one was derived from, or null. A wildcat and its parent case, for example.

Year it entered production or service. Null where the date is disputed or unknown.

Person or team credited with the design, where it is known.

Page the dimensions were read from.

The standards body whose figures these are (SAAMI, CIP), where the source names one.

How completely the record is specified and how well it is sourced, 0 to 1. A record-level completeness and provenance measure, not a per-field probability of correctness. Use it to rank and triage; use sources to verify an individual number.

When a person last checked this record against its source. Null means nobody has: the row is model knowledge until then.

JSON array of the fields the source stated.

When the record was first added, YYYY-MM-DD HH:MM:SS in UTC.

When a field we serve last changed. Maintained by the database rather than by whatever wrote the row, so it moves for a corrected specification and does not move for a re-run of the importer.

Opaque fingerprint of this record. It changes when and only when a field we serve changes, so a client holding the same value already has the record and need not fetch it. Equality is the only supported operation: do not parse it, and do not assume how it is computed. Null means the record has not been written since versioning began, not that it is unchanged.

Where a record's figures came from and how far they have been checked, in one place. sources are the pages consulted; check a specific figure against those. sourceKinds says what each page is and bestSourceKind the strongest of them, on the hierarchy SourceKind defines: a maker or standards-body page is evidence for a figure, a retailer or forum page is evidence the item exists. dataConfidence is the 0 to 1 score set from what was actually sourced and never raised by hand. verifiedAt and verifiedFields say when a source was last read against the record and which fields it stated; null means the row is still seed knowledge. updatedAt and version are the same cache signals the record carries at the top level.

The pages consulted when the record was compiled, as an array. Check a specific figure against these rather than against dataConfidence.

What each cited page is, in sources order, on the SourceKind hierarchy. A host not in the source map is other, never guessed.

The strongest kind among the citations, or null when nothing is cited. manufacturer or standards_body means a figure can be checked against an authority; retailer or community alone means the record is still supported by copies of copies.

The 0 to 1 score set from what was actually sourced, never raised by hand. See the confidence bands in the docs.

When a source was last read against this record. Null means the row is still seed knowledge.

Which fields the source stated, as an array. Everything else on a verified row is still unverified. Null where no source has been read.

Cartridges only: the page the drawing figures were taken from. Null on every other kind of record.

When a served column last changed; the same value the record carries at the top level.

The record's content version, equal to the top-level version; equal versions mean equal data.