Across the 33 calibers eligible in IronScout's tracked data this week, the picture is unusually one-directional: the median seven-day move across the 28 calibers with usable baselines was −2.9%, declines outnumbered increases by a wide margin, and tracked in-stock product counts rose almost everywhere. All figures below are observed daily-best medians over a rolling 30-day window, from tracked online retailers — recorded history, not a projection.
The decliners
Handgun calibers led the move down over the seven days to July 17:
| Caliber | 7-day move | 30-day move | Observed median now |
|---|---|---|---|
| 9mm | −16.6% | −38.4% | $0.600/rd |
| .380 ACP | −15.5% | −24.2% | $0.758/rd |
| .223/5.56 | −13.9% | −28.0% | $0.900/rd |
| .38 Special | −13.0% | −22.7% | $0.800/rd |
| .32 ACP | −9.0% | −11.6% | $0.610/rd |
| .45 ACP | −8.7% | −16.0% | $1.050/rd |
| .40 S&W | −7.9% | −31.6% | $0.736/rd |
| .300 Blackout | −5.7% | −17.5% | $1.320/rd |
Several of these are on multi-week runs: 9mm, .223/5.56, .40 S&W, and .300 Blackout have each recorded four consecutive week-over-week declines in the observed median; .380 ACP, .38 Special, and .32 ACP have recorded three.
One caliber shows how the weekly and monthly views can differ: 7.62x39 was essentially flat on the week (−0.2%, $0.850 → $0.848/rd) but is down 26.3% over thirty days, with its own four-week decline streak — the big move happened earlier in the window.
Shelves got deeper almost everywhere
The declines came with rising in-stock counts, not falling ones. Tracked in-stock product counts over the same seven days: 9mm 619 → 714 (+15.3%), .223/5.56 649 → 715 (+10.2%), .38 Special 210 → 250 (+19.0%), 7.62x39 90 → 115 (+27.8%), .300 Blackout 199 → 232 (+16.6%).
That pairing matters for reading the price moves. The observed in-stock median falls both when prices drop and when cheaper products come back in stock — and this week shows clear evidence of restocking. The 9mm deep-dive walks through that composition effect in detail; it applies across the board.
The outlier: 20 gauge
One caliber moved against everything else. 20 gauge rose +4.0% on the week ($0.880 → $0.916/rd) and +9.0% over thirty days — while the median move across the 28 eligible tracked calibers was −2.9%. Its tracked in-stock count also jumped 197 → 255 (+29.4%), the largest availability increase of the week.
A per-round figure for a shotgun gauge blends very different shell types, so mix effects cut especially strongly there — but the direction of the divergence is the observed fact: 20 gauge got more expensive in a week when nearly everything else got cheaper in the tracked data.
Where to watch the numbers
Per-caliber medians, distribution bands, and six-month trends are updated daily on the Ammo Price Index. Each caliber page linked above carries its own live pricing context and price history.
Source: IronScout caliber market snapshots computed 2026-07-17 ~13:00 UTC, with 7- and 30-day baselines from the same snapshot series. Figures are observed daily-best per-round medians from tracked online retailers, in stock at observation time; they may not reflect the entire market. Market context only — not a recommendation.