IMR Classic
IMR 4227
Hodgdon positions IMR 4227 as a medium burn speed magnum handgun propellant, and it is the IMR line's designated choice for full-power magnum revolver loads. It also serves small-capacity rifle cartridges such as the 22 Hornet and 221 Fireball.
Specifications
| Manufacturer | IMR |
|---|---|
| Product family | IMR Classic |
| Status | Currently produced |
| Application | pistol, rifle |
| Grain form | extruded |
| Composition | single-base |
| Temperature stable | Not marketed as temperature-stable |
| Burn-rate position | 76 of 198 (fastest = 1) — what this means |
| Typical cartridges | 357 Magnum, 44 Magnum, 22 Hornet, 221 Remington Fireball |
Extruded single-base powder, made in Canada. Hodgdon does not list it as temperature stable, and flags it as suitable for subsonic work.
Burn rate
Slow for a handgun powder — sits just past the magnum-pistol ball powders and at the very fast end of the rifle range.
Chart agreement: consistent across the three charts that list it Ranked by: Hodgdon, Shooters World, Wolfe/LoadData.
Powders charted near it — neighbours on the chart are not substitutes, and adjacency tells you nothing about what charge either one takes:
- Hodgdon H110 (position 73)
- Winchester 296 (position 74)
- Accurate No. 11FS (position 75)
- Hodgdon H4227 (position 77)
- Alliant Power Pro 300-MP (position 78)
- Accurate 5744 (position 79)
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.