IMR Enduron
IMR Enduron 4166
A match-grade medium-speed rifle powder covering mid-capacity cartridges. Hodgdon states it performs comparably to Hodgdon Varget while stressing that charge weights are materially different and data must not be crossed over.
Specifications
| Manufacturer | IMR |
|---|---|
| Product family | IMR Enduron |
| Status | Currently produced |
| Application | rifle |
| Grain form | extruded |
| Composition | single-base |
| Temperature stable | Yes — claimed by the manufacturer |
| Burn-rate position | 118 of 198 (fastest = 1) — what this means |
| Typical cartridges | 308 Winchester, 7.62mm NATO, 22-250 Remington, 257 Roberts |
Enduron powders are marketed on four shared claims: a copper fouling eliminator additive, reduced sensitivity to temperature change, loading density matched to the intended cartridge class, and a REACH-compliant formulation. Extruded single-base, made in Canada.
Burn rate
Fastest of the five Enduron powders; medium rifle speed, essentially alongside IMR 4064.
Chart agreement: consistent, but single-publisher - ranked only by Hodgdon (and echoed by the Wolfe/LoadData compilation). No second manufacturer's chart carries it, so the position is uncorroborated. Ranked by: Hodgdon, Wolfe/LoadData.
Powders charted near it — neighbours on the chart are not substitutes, and adjacency tells you nothing about what charge either one takes:
- Vihtavuori N135 (position 115)
- Accurate 2495 (position 117)
- IMR 4064 (position 119)
- Norma 202 (position 120)
- Accurate 4064 (position 121)
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.