IMR Classic
IMR 4320
A general-purpose medium-speed rifle powder that served mid-capacity varmint and standard hunting cartridges before it was dropped.
Discontinued. Canisters still circulate, but the maker no longer produces it — and load data for it may be withdrawn or archived.
Specifications
| Manufacturer | IMR |
|---|---|
| Product family | IMR Classic |
| Status | Discontinued |
| Application | rifle |
| Grain form | extruded |
| Composition | single-base |
| Typical cartridges | 308 Winchester, 30-06 Springfield, 22-250 Remington, 220 Swift |
Discontinued. Hodgdon no longer lists this powder among current IMR products and it does not appear on Hodgdon's current relative burn rate chart. Historical published data for it may still appear in older Hodgdon and IMR manuals; check the current Reloading Data Center before assuming coverage.
Data confidence
We flag entries we could not fully verify rather than presenting them as solid:
- Discontinued — no live manufacturer product page; details drawn from archived or secondary manufacturer material.
Sources
Other IMR powders
Verify the charge, not just the recipe
Good data gets you a safe starting point. It does not tell you what actually went into the case on stroke 340 — a bridged measure, a double charge, a squib. That is what an RCM Laser Powder Check is for.