Methods
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 densitiesThe density of every material a mass check reads, each quoted from the page that states it.Cartridge massThe mass of one loaded round from its bullet and its case, fitted to cartridges whose mass a source states.Loaded weightHow much a full magazine should add to a gun's empty weight, and the test a record's two weights must pass.Apparent densityA gun's empty weight over its bounding box, judged against guns of the same category and frame material.Cartridge arithmeticEnergy, pressure, sectional density, calibre and velocity: the figures a cartridge record holds that must agree with one another.Physical boundsLimits 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.TrajectoryHow 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.Check thresholdsThe 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.Ballistic figuresThe 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.Similar firearmsHow 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.Name matchingHow 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.Fitment engineHow 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.ComparisonsWhat 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.Sources and quotesHow a figure's evidence is ranked, how a reference work is followed to the pages it cites, and the quote every figure must carry.Source registryEvery 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.ReferencesEvery page the methods take a figure from, numbered once, with what it supports.