Scope of this comparison
This page covers centerfire handgun calibers only. Rimfire is a different cost class entirely — see Cheapest Calibers to Shoot for the cross-category picture, and .22 LR for the rimfire figures.
Every figure linked from this page is an observed cost per round: the lowest in-stock price seen per distinct product per day, aggregated over a rolling 30-day window across tracked retailers. Coverage varies by caliber, and observation counts are published on each caliber page. Prices move; the linked pages carry the current numbers rather than a snapshot frozen into this article.
Why 9mm sits at the bottom
9mm is the highest-volume centerfire handgun cartridge manufactured, and that volume is the dominant cost factor. Three things follow from it:
Production scale. Per-unit cost falls as run length rises. 9mm runs are the longest in the industry, so fixed tooling and setup costs spread across far more rounds than any other centerfire pistol caliber.
Material mass. A 9mm 115gr FMJ uses substantially less lead and copper than a .45 ACP 230gr FMJ — roughly a third of the projectile mass. Material cost sets a floor that competition cannot push through, which is why heavier calibers stay structurally more expensive regardless of demand.
Competitive density. More manufacturers produce 9mm than any other handgun caliber, including importers. Retail competition is correspondingly tighter.
Where the other pistol calibers land
.380 ACP uses less material than 9mm but runs at lower volume, and the two effects partly cancel. It does not reliably land below 9mm despite the smaller projectile — a common assumption that the observed data does not support.
.38 Special and .357 Magnum are revolver cartridges with smaller production runs. .357 Magnum carries a powder-charge premium over .38 Special in the same case family.
.40 S&W occupies a shrinking market as agencies and civilians moved back to 9mm. Falling volume works against it.
.45 ACP carries the heaviest common pistol projectile in this set, and its cost reflects the material mass directly.
10mm Auto is the smallest-volume caliber here and typically the most expensive per round, combining a niche market with a heavy projectile and a full-power charge.
What changes the ordering
The ranking above is structural and moves slowly. What moves faster:
- Case material. Steel-cased and aluminum-cased loads price below brass in the same caliber. See Steel Case vs Brass Case for the durability and reloading tradeoffs.
- Bullet construction. FMJ range loads and JHP defensive loads in the same caliber are different cost classes. Comparing a defensive load in one caliber against a range load in another produces a misleading gap — see FMJ vs Hollow Point.
- Pack size. Per-round cost falls with case quantity at most retailers.
Current figures
Each caliber page carries its observed range, median, lower quartile, observation count, and contributing retailer count for the current window:
9mm · .380 ACP · .38 Special · .40 S&W · .45 ACP · .357 Magnum · 10mm Auto
Related articles
- Cheapest Calibers to Shoot — all categories, rimfire through rifle
- Cheapest Centerfire Rifle Calibers — the rifle equivalent of this page
- 9mm vs .45 ACP · 9mm vs .40 S&W · 9mm vs .380 ACP
- Same Ammo, Different Prices — why identical loads vary across retailers