# Methods Source: https://docs.gunspec.io/en/methods/overview How every data check calculates, one model to a page: the equations, the published figures each was fitted to, a record worked through, and the sources the numbers come from. ## How a method is written - Every number on these pages is computed by the module the check runs, so a page cannot disagree with its check. - A constant is fitted to figures a source states, and the table it was fitted to is shown beside it with how far the model lands from each. - A band is wider than the fit needs where the model has nothing to fit to (rimfire, the largest rounds), and the page says so. - One real record is worked through with its own numbers substituted, ending on the band and its answer. - No figure is estimated. A value with no quotable source is left out of the model and out of the registry. ## The methods [Material densities The density of every material a mass check reads, each quoted from the page that states it.](https://docs.gunspec.io/en/methods/materials) [Cartridge mass The mass of one loaded round from its bullet and its case, fitted to cartridges whose mass a source states.](https://docs.gunspec.io/en/methods/cartridge-mass) [Loaded weight How much a full magazine should add to a gun's empty weight, and the test a record's two weights must pass.](https://docs.gunspec.io/en/methods/loaded-weight) [Apparent density A gun's empty weight over its bounding box, judged against guns of the same category and frame material.](https://docs.gunspec.io/en/methods/apparent-density) [Cartridge arithmetic Energy, pressure, sectional density, calibre and velocity: the figures a cartridge record holds that must agree with one another.](https://docs.gunspec.io/en/methods/cartridge-arithmetic) [Physical bounds Limits no gun can break: how far a projectile can fly with no air, how fast a gun is pushed back by its bullet, and the order things happen in.](https://docs.gunspec.io/en/methods/physical-bounds) [Statistical anomalies How a figure is judged unusual for its kind: a robust score on logarithms against a family or a cohort of like guns, the figures it reads and the ones it leaves alone, and what a record may say to explain itself.](https://docs.gunspec.io/en/methods/statistical-anomalies) [Trajectory How the API flies a bullet: the drag it steps through, the air it flies in, how a drop becomes a path from the line of sight, and what it assumes.](https://docs.gunspec.io/en/methods/trajectory) [Check thresholds The thresholds the record and source checks judge by: plausibility, integrity, manufacturers against Wikidata, corroboration and links. What each measures, where the line is, and what crossing it means.](https://docs.gunspec.io/en/methods/check-rules) [Ballistic figures The figures printed beside a trajectory: the effective range, and the energy, momentum, knock-out factor, sectional density, relative stopping power and energy density at the muzzle. How each is worked out, and which inputs a record may not hold.](https://docs.gunspec.io/en/methods/ballistic-figures) [Similar firearms How the similar firearms answer is ranked: a weighted sum of what two guns share, each trait with a band for its whole weight and one for half, worked through on two real records.](https://docs.gunspec.io/en/methods/similarity) [Name matching How a name becomes a record: the score the resolver gives each spelling it knows, when it answers, when it says the name is ambiguous, and the order search results come back in.](https://docs.gunspec.io/en/methods/name-matching) [Fitment engine How the compatibility engine decides whether a part fits a gun: the order it asks in, the caliber gate, where a part may sit, one adapter at most, and how a fit's confidence is set.](https://docs.gunspec.io/en/methods/fitment) [Comparisons What the compare answers compute: the spread of each figure across the compared records, and the head-to-head's winner per figure, with the direction it treats as better stated as the choice it is.](https://docs.gunspec.io/en/methods/compare) [Load carriage What a foot march costs in energy carrying each firearm, its full magazines and its attachments on top of the rest of the kit, by two published load-carriage equations, and what those equations leave out.](https://docs.gunspec.io/en/methods/load-carriage) [Free recoil How fast, how hard and with how much energy a firearm free to move is pushed back by one shot, by the formula SAAMI publishes, and why without a powder charge the figure is a lower bound.](https://docs.gunspec.io/en/methods/recoil) [Point-blank range The furthest distance a bullet stays within a target's radius of the line of sight with no holdover, the zero that gives it, and how far the bullet stays supersonic, on the computed trajectory.](https://docs.gunspec.io/en/methods/point-blank) [Ammunition per kilogram Rounds per kilogram of full magazines and what a weight budget holds, derived from the record, and a basic load's mass estimated by the fitted cartridge-mass model with its error as a range.](https://docs.gunspec.io/en/methods/ammo-load) [How Redback works a task Redback is the agent that works the data quality queue. This page follows one task from the check that raised it to the record a person may change, and says at each step what is done by code, what is asked of a model, and what is left to a person.](https://docs.gunspec.io/en/methods/redback-pipeline) [How a figure is held to its evidence Before any figure Redback finds reaches a reviewer, it is held to four rules in a fixed order: the page can be cited, the quote is on it, the page is about this gun, and the figure fits the record. This page states each rule, what it refuses, what it only doubts, and why.](https://docs.gunspec.io/en/methods/redback-evidence) [How Redback chooses its models and tools Redback is not one model. Each job inside a task (reading excerpts, checking a reading, reading again when in doubt, judging a contradiction, placing a spelling) is its own request, with its own chain of models chosen for what that job needs. Code does the searching and fetching, and keeps what it has paid for. This page describes how a job gets its model, how a call finds a working key, how search works, and what is kept and for how long.](https://docs.gunspec.io/en/methods/redback-tools) [What Redback learns, and who decides Redback keeps what it finds out between runs, and the rule for what it may keep is the distinction between a measurement and a claim. A measurement is kept as it is taken; a claim waits for a person. This page describes each kind of memory and the way both reach the reviewed catalogue.](https://docs.gunspec.io/en/methods/redback-learning) [How Redback is measured Whether Redback's figures are right is measured, not assumed. Figures we already hold with a checked quote are hidden, Redback researches each one as it would any gap, and code scores what comes back. This page describes the design, the scoring and the results so far.](https://docs.gunspec.io/en/methods/redback-measurement) [One Redback task, end to end The other Redback pages each describe one part. This one puts them together: every stage a task passes through, who or what does it, what each stage produces and where that output goes, followed through a real run from the blind measurement.](https://docs.gunspec.io/en/methods/redback-end-to-end) [Sources and quotes How a figure's evidence is ranked, how a reference work is followed to the pages it cites, and the quote every figure must carry.](https://docs.gunspec.io/en/methods/sources) [Source registry Every site the catalogue cites, what kind of source it is and on what basis, and how many records cite it. Authorities carry the verified mark.](https://docs.gunspec.io/en/methods/source-registry) [References Every page the methods take a figure from, numbered once, with what it supports.](https://docs.gunspec.io/en/methods/references)