Ammo price methodology
How cost per round is calculated
Cost per round is the most useful way to compare ammo prices, but only when round count, pack size, and product type are parsed carefully.
Default offer and best known CPR
Ammo product pages keep the retailer's displayed/default offer as the main product price, while structured pack-size data can also show the best known CPR from larger quantity tiers when the source exposes them.
No invented middle tiers
If a retailer page exposes a default price and a max tier but hides intermediate tier prices, Firearm Data Lab stores the unpriced options as unpriced rather than inventing CPR values.
Plausibility guardrails
Public ammo stats apply caliber-specific CPR floors and ceilings so storage boxes, components, variant flips, or parser mistakes do not pollute lowest CPR, median CPR, or deal surfaces.