Published: 2026 | Last updated: May 2026
IMR 4227 is a fast-burning, single-base short-cut extruded powder – the fastest-burning powder in the current IMR rifle series. Originally developed by DuPont and now distributed by Hodgdon Powder Company as part of the IMR lineup, it occupies the burn rate bridge between heavy magnum handgun powders and small-bore rifle powders: slower than Hodgdon H110 and Winchester 296, faster than Hodgdon H4198.
This position gives IMR 4227 a specific practical role that ball powder alternatives in the same burn rate range cannot fully replicate: it is the single-base extruded choice for applications where cast bullet compatibility, broad pressure range flexibility, and lower flame temperature are the priorities over ball powder metering consistency. In 300 Blackout subsonic loading, 22 Hornet varminting, and 44 Magnum cast bullet hunting loads, the single-base chemistry and linear pressure curve produce results that the double-base ball powders at comparable burn rates cannot match in the same way.
Understanding where this burn rate position fits in the overall fast-rifle / magnum-handgun spectrum, and where its specific properties are advantageous versus where Accurate 1680 or Hodgdon H110 are better choices, is the starting context for correct application.
This article is based on published manufacturer specifications, established load data, and documented field reports. Specifications and performance figures can vary between lots, rifles, and conditions. If you have loaded IMR 4227 in practice – leave a comment below: real-world experience from the reloading bench is what separates verified data from manufacturer claims.
Powder Description and Technical Profile
IMR 4227 is a single-base, short-cut extruded cylindrical powder. The single-base formulation – nitrocellulose without nitroglycerin – is the defining chemistry that separates it from the double-base ball powders in the same burn rate class.
Single-base chemistry produces three practically important consequences at this burn rate position:
Lower flame temperature than double-base alternatives. In a 44 Magnum revolver barrel or a 300 Blackout suppressor, less thermal energy per shot means less bore erosion and less carbon accumulation from high-temperature incomplete combustion. For a suppressed 300 Blackout shooter, the difference in suppressor carbon accumulation between a single-base and double-base powder at the same burn rate is measurable over a shooting session.
More complete combustion at moderate pressures. Double-base ball powders like Hodgdon H110 require near-maximum pressure for complete combustion. IMR 4227 burns more completely across a broader pressure range from its single-base extruded chemistry. Reduced-velocity loads with IMR 4227 burn more cleanly than equivalent reduced loads with H110. This is the mechanism behind its cast bullet reputation.
Predictable linear pressure curve throughout the working pressure range. The pressure builds progressively rather than in the stepped pattern that can affect double-base powders at varying temperature and charge level combinations. This linearity produces the consistent acceleration that cast bullet shooters describe as a “push rather than a kick.”
The short-cut extruded grain geometry is the metering improvement over traditional long-stick extruded powders. Kernels are cut shorter than standard IMR sticks, reducing bridging and shearing in the measure drum. The practical result is metering variance of approximately ±0.1-0.15 grains on quality equipment – better than long-stick extruded powders but not at ball powder performance levels.
Bulk density is approximately 0.900-0.940 g/cc – high for a single-base extruded powder in this burn rate class. This density provides good case fill in the primary applications: 22 Hornet at 92-96% fill at working charges, 300 Blackout subsonic with 200-220 grain bullets at approximately 85-93% fill.
Strengths:
- Single-base chemistry produces cleaner burning at moderate and reduced pressures than double-base ball alternatives – specifically valuable for cast bullet loads and suppressed shooting
- No minimum pressure requirement unlike Hodgdon H110 – loads can be reduced without the dangerous erratic combustion that H110 produces below minimum working pressure
- Linear pressure curve compatible with cast lead bullets at full-pressure magnum velocities and moderate target velocities
- Lower flame temperature – less suppressor carbon accumulation than double-base alternatives in 300 Blackout suppressed applications
- Short-cut geometry meters better than traditional long-stick IMR powders – ±0.1-0.15 grains on quality equipment
- Single-base temperature stability better than double-base alternatives at the same burn rate (approximately 1.1-1.3 fps/°F vs Alliant 2400’s 1.4-1.6 fps/°F)
Limitations:
- Meters less consistently than ball powders – Accurate 1680, Hodgdon H110, and similar spherical powders produce ±0.04-0.07 grain variance versus 4227’s ±0.1-0.15 grains
- Temperature sensitivity (1.1-1.3 fps/°F) – moderate; better than Alliant 2400 and Alliant 2400 but significantly more sensitive than the Extreme or Enduron series
- Not appropriate for medium or large-capacity rifle cartridges – too fast for 308 Winchester and similar cases at standard bullet weights
- Short-cut grains can occasionally bridge in narrow progressive press drop tubes with very small apertures – verify powder bar sizing for the grain dimensions
Technical Characteristics
| Property | Specification |
|---|---|
| Manufacturer | IMR (Hodgdon Powder Company) |
| Heritage | DuPont original formulation |
| Type | Single-Base Short-Cut Extruded |
| Bulk Density (g/cc) | ~0.900 – 0.940 |
| Burn Rate Category | Fast Rifle / Slow Magnum Handgun |
| Fastest in IMR Series | Yes |
| Temperature Sensitivity | ~1.1-1.3 fps / °F |
Where IMR 4227 Fits in the Fast-Rifle / Magnum-Handgun Spectrum
IMR 4227 is not the only powder in the fast-rifle / magnum-handgun burn rate class, and understanding its specific position relative to its neighbors is the key to appropriate application:
| Powder | Type | Faster/Slower | Key Distinction |
|---|---|---|---|
| Hodgdon H110 | Double-Base Ball | Faster | Max pressure only, magnum primer required |
| Winchester 296 | Double-Base Ball | Faster | = H110 |
| Alliant 2400 | Double-Base Disc | Slightly Faster | Broader pressure range, no mag primer |
| IMR 4227 | Single-Base Extruded | Reference | Clean burning, cast bullets, suppressed |
| Accurate 1680 | Double-Base Ball | Slightly Slower | 7.62×39, 300 BLK subsonic specialist |
| Vihtavuori N110 | Single-Base Extruded | Similar | Better temperature stability |
| Hodgdon H4198 | Single-Base Extruded | Slower | Extreme stability |
IMR 4227 occupies a position that two adjacent powders specifically do not cover:
- H110 is faster and requires near-maximum pressure at all times
- Accurate 1680 is a double-base ball powder with superior metering but less cast bullet compatibility and more suppressor residue
The reloader who needs the fast-rifle / magnum-handgun burn rate with single-base chemistry, broad pressure range, and cast bullet compatibility has two options: IMR 4227 and Vihtavuori N110. N110 has better temperature stability; IMR 4227 has deeper North American published data.
Temperature Stability – Context
1.1-1.3 fps per degree Fahrenheit places IMR 4227 in the moderate sensitivity range – meaningfully better than Alliant 2400 at 1.4-1.6 fps/°F, and slightly better than Accurate 1680 at 1.0-1.5 fps/°F. Both are double-base powders; IMR 4227’s single-base chemistry inherently reduces temperature sensitivity from the simpler energy release mechanism.
The practical impact depends on application:
300 Blackout subsonic: At 200-220 grain bullet loads near the cycling threshold, a 60°F temperature swing (summer development to winter use) produces approximately 66-78 fps velocity variation – potentially enough to drop below the cycling threshold in cold weather. The original article correctly identifies this as a specific concern. For a suppressed 300 Blackout shooter who develops loads in summer, verifying cycling at the coldest expected operating temperature is essential.
22 Hornet varminting: At 300-yard prairie dog distances, a 60°F seasonal swing produces roughly 1-1.5 inches of additional vertical variation. Manageable with a temperature-corrected drop chart.
Magnum revolver hunting: At typical handgun hunting distances (under 100 yards), the velocity variation from a seasonal swing is within the practical hunting margin.
| Powder | 60°F Swing | 300 BLK subsonic concern |
|---|---|---|
| IMR 4227 | ~66-78 fps | Moderate – verify cycling in cold |
| Accurate 1680 | ~60-90 fps | Moderate – similar |
| Hodgdon H4198 | ~18 fps | Minimal |
| Vihtavuori N110 | ~24-36 fps | Low |
Burn Rate Comparison and Competing Powders
| Powder | Type | Density (g/cc) | Key Character |
|---|---|---|---|
| Hodgdon H110 | Double-Base Spherical | 0.930 | Faster – max pressure only |
| Alliant 2400 | Double-Base Disc | 0.873 | Slightly Faster – broad pressure range |
| Vihtavuori N110 | Single-Base Extruded | 0.800 | Similar – better stability |
| IMR 4227 | Single-Base Short-Cut Extruded | 0.920 | Reference |
| Accurate 1680 | Double-Base Spherical | 0.960 | Slightly Slower – ball metering |
| Hodgdon CFE BLK | Double-Base Spherical | 0.940 | Slightly Slower – 300 BLK dedicated |
| Hodgdon H4198 | Single-Base Extruded | 0.850 | Slower – Extreme stability |
vs. Accurate 1680: The most direct competition for 300 Blackout subsonic and 7.62x39mm. 1680 is a double-base ball powder with superior metering (0.04-0.07 grain variance) and slightly better-documented subsonic 300 Blackout cycling reliability. IMR 4227 produces less suppressor residue from single-base chemistry and has better cast bullet compatibility. For high-volume progressive production of 300 Blackout subsonic, 1680’s ball metering advantage is practically significant. For single-stage precision subsonic loading with suppressor cleanliness as a priority, IMR 4227 is the more appropriate choice.
vs. Hodgdon H110: H110 is faster, requires near-maximum pressure at all times, and needs magnum primers. IMR 4227 works across a broader pressure range, does not require magnum primers for most applications, and is compatible with cast bullet reduced-velocity loads. For maximum-velocity jacketed bullet 44 Magnum or 357 Magnum with ball metering, H110 is the better choice. For cast bullet 44 Magnum across a range of pressures, IMR 4227 is more appropriate.
vs. Vihtavuori N110: The most technically similar competitor – both single-base extruded powders at comparable burn rates with good cast bullet compatibility. N110 has measurably better temperature stability (0.4-0.6 fps/°F vs 1.1-1.3 fps/°F). IMR 4227 has a deeper North American published data library and is typically more available and less expensive. For precision suppressed 300 Blackout where temperature consistency is important, N110 is the more appropriate choice. For general-purpose applications where data availability and price matter, IMR 4227 is the practical choice.
vs. Hodgdon H4198: H4198 burns slightly slower and belongs to the Extreme series with 0.2-0.4 fps/°F stability – substantially better than IMR 4227. It is the more appropriate choice for 22 Hornet year-round varmint hunting where seasonal temperature consistency matters. IMR 4227 has a specific advantage in 44 Magnum and 300 Blackout subsonic where the burn rate is better matched to those applications than H4198.
Recommended Cartridges and Applications
IMR 4227 operates efficiently in the same burn rate niche as Alliant 2400 and Hodgdon H110, with specific advantages in applications where single-base chemistry matters.
| Cartridge | Bullet Weight | Application |
|---|---|---|
| 300 Blackout | 200-220 gr | Subsonic suppressed – primary modern use |
| 22 Hornet | 35-55 gr | Maximum velocity varmint |
| 44 Magnum | 200-300 gr | Cast and jacketed hunting loads |
| 357 Magnum | 125-180 gr | Hunting and sporting |
| 454 Casull | 250-360 gr | High-pressure hunting |
| 45 Colt | 250-325 gr | Near-maximum specialty loads |
| 30 Carbine | 110 gr | Carbine velocity loads |
| 7.62x39mm | 123-125 gr | Bolt-action precision |
| 41 Remington Magnum | 200-265 gr | Full-pressure hunting |
The 300 Blackout subsonic application is where IMR 4227 has its strongest modern differentiation. With 200-220 grain bullets at velocities below 1,050 fps, the single-base chemistry produces substantially less carbon accumulation in suppressors than double-base ball powders like Accurate 1680. For a shooter who fires 200+ subsonic rounds per session through a suppressed AR-15 without disassembling and cleaning the suppressor between sessions, the difference in carbon accumulation is practically significant – extending the interval before baffle cleaning becomes necessary for reliable tone and sound performance.
The 300 Blackout subsonic temperature caveat applies directly: verify cycling at the coldest expected operating temperature. A load that reliably cycles a bolt carrier group at 70°F may drop below cycling threshold at 15°F with 1.1-1.3 fps/°F temperature sensitivity over a 55°F swing.
The 44 Magnum cast bullet application benefits from the same cleanliness principle. Cast alloy bullets typically have more sensitivity to bore fouling than jacketed, and a powder that produces less residue per shot keeps the bore cleaner longer through a hunting session.
Bullets
IMR 4227 works with jacketed, plated, and cast lead bullets across its application range. The linear pressure curve from single-base extruded chemistry produces the least bullet upset at the base of cast projectiles compared to double-base ball powders at equivalent velocities.
| Brand | Model | Weight | Cartridge | Application |
|---|---|---|---|---|
| Sierra | MatchKing | 200-220 gr | 300 Blackout | Subsonic Precision |
| Hornady | A-Tip Match | 200-220 gr | 300 Blackout | Premium Subsonic |
| Sierra | Sports Master | 240-300 gr | 44 Magnum | Hunting |
| Hornady | XTP | 158-300 gr | 357 Mag / 44 Mag | Hunting and Defense |
| Nosler | Partition | 250-300 gr | 44 Magnum | Big Game Hunting |
| Barnes | TSX | 200-275 gr | 44 Magnum / 454 Casull | Lead-Free Hunting |
| Hornady | V-MAX | 40-55 gr | 22 Hornet | Varmint |
| Sierra | Varminter | 40-50 gr | 22 Hornet | Varmint |
| Lapua | FMJ | 123-125 gr | 7.62x39mm | Precision Practice |
| Lehigh Defense | Match Solid | 194-204 gr | 300 Blackout | Precision Subsonic |
Have you loaded IMR 4227? Your practical data on charge weights, 300 Blackout subsonic cycling, cast bullet accuracy, or suppressor fouling experience helps other reloaders more than any spec sheet. Leave a comment below.
Primers
IMR 4227 as a single-base extruded powder without heavy deterrent coating ignites well from standard small rifle primers in most small-bore rifle applications. For large-bore revolver applications, standard large pistol primers are generally adequate at sub-maximum charges; at maximum charges in 454 Casull and similar high-pressure applications, magnum large pistol primers provide more reliable ignition. This contrasts directly with Hodgdon H110 which requires magnum primers at all times.
| Primer | Type | Application |
|---|---|---|
| CCI 400 | Small Rifle Standard | 22 Hornet, 300 BLK general |
| Federal 205 | Small Rifle Standard | Consistent small case ignition |
| CCI No. 41 | Small Rifle Magnum (Mil-Spec) | AR-15 semi-auto 300 BLK |
| CCI 450 | Small Rifle Magnum | Cold weather, 300 BLK dense loads |
| Winchester WSR | Small Rifle Standard | 7.62x39mm, 22 Hornet |
| Remington 7-1/2 | Small Rifle Bench Rest | 22 Hornet – hot ignition |
| RWS 4033 | Small Rifle | Premium European option |
| CCI 300 | Large Pistol Standard | 44 Magnum, 357 Magnum standard loads |
| Winchester WLP | Large Pistol Standard | 44 Magnum general use |
| CCI 350 | Large Pistol Magnum | 454 Casull, maximum 44 Mag loads |
| Federal 215 | Large Rifle Magnum | 454 Casull maximum pressure |
| Fiocchi Small Rifle | Small Rifle Standard | Volume production alternative |
For AR-15 semi-automatic 300 Blackout, the CCI No. 41 mil-spec primer cup prevents slam-fire from a free-floating firing pin. For subsonic loads where case fill is modest, the CCI 450 small rifle magnum provides more reliable ignition in cold-weather conditions.
Metering and Equipment Compatibility
IMR 4227’s short-cut grain geometry provides better metering than traditional long-stick extruded powders. On quality volumetric equipment, ±0.1-0.15 grain variance is typical. This is adequate for hunting and general handgun loading; for benchrest-grade precision, hand-weighing or an auto-dispenser improves on this.
For progressive press 300 Blackout and 7.62x39mm production on a Dillon XL 750 or Hornady Lock-N-Load AP, verify that the powder bar aperture is sized to handle IMR 4227’s grain dimensions without bridging. The short-cut geometry handles progressive cycling better than long-stick IMR powders.
For single-stage precision loading, a Frankford Arsenal Powder Trickler with a high-resolution scale like the RCBS MatchMaster or Lyman Gen 6 Compact provides ±0.02 grain charge precision for 300 Blackout subsonic accuracy work.
Reloading Safety Notes
All charge weights must come from current published IMR/Hodgdon load data for IMR 4227 specifically. Do not substitute Accurate 1680, Hodgdon H110, or Vihtavuori N110 charge weights without independent verification. The density and chemistry differences are large enough that charge weights are not interchangeable.
300 Blackout subsonic temperature protocol: develop and verify cycling at the coldest temperature you will operate the firearm. A load that cycles reliably at 70°F may fall below cycling threshold at 15°F with 1.1-1.3 fps/°F sensitivity over a 55°F swing. Verify function at field temperatures before depending on the load.
Start 10% below the listed maximum and work up in 0.2-grain increments for small cases like 22 Hornet and 300 Blackout, 0.3-grain increments for revolver cartridges. Watch for pressure signs: flattened primers, stiff extraction, ejector marks.
See the overpressure in reloading guide for systematic pressure sign identification.
FAQ
Is IMR 4227 better than Accurate 1680 for 300 Blackout subsonic?
They serve the same application from different design positions. Accurate 1680 is a double-base ball powder with better metering (0.04-0.07 grain variance) and documented subsonic AR-15 cycling reliability. IMR 4227 is a single-base extruded powder with less suppressor carbon accumulation and better cast bullet compatibility. For high-volume progressive production where metering efficiency matters, 1680 is more practical. For precision single-stage subsonic loading where suppressor cleanliness is important, IMR 4227 is more appropriate.
Can IMR 4227 be used for standard 300 Blackout supersonic loads with 110-125 grain bullets?
Published data exists for IMR 4227 in 300 Blackout supersonic, but Hodgdon CFE BLK, Vihtavuori N110, and Accurate 1680 are generally better matched to the supersonic 300 Blackout application. IMR 4227 is most specifically appropriate for the subsonic role where its slower burn and single-base cleanliness are most valuable.
Does IMR 4227 require magnum primers like H110?
No – this is a direct advantage over Hodgdon H110. Standard large pistol primers work for most IMR 4227 revolver applications; small rifle primers work for rifle applications. Magnum primers are appropriate at maximum charges in 454 Casull and in cold weather below 15°F. H110 requires magnum primers in all applications due to its heavy deterrent coating.
Conclusion
IMR 4227 fills a specific position in the fast-rifle / magnum-handgun burn rate class that double-base ball powder alternatives cannot replicate: single-base chemistry for suppressor cleanliness and cast bullet compatibility, short-cut extruded geometry for adequate metering consistency, no minimum pressure requirement for broad working range flexibility.
Its temperature sensitivity (1.1-1.3 fps/°F) is the honest limitation – better than most double-base alternatives in the class but requiring verification for 300 Blackout subsonic cycling across seasonal temperatures. Its metering is adequate for hunting and general precision loading but not at ball powder levels.
Choose IMR 4227 if you load 300 Blackout subsonic for suppressed use and prioritize suppressor cleanliness, or if you load 44 Magnum and 357 Magnum with cast bullets across a range of pressures. Choose Accurate 1680 if progressive press production metering consistency and documented subsonic 300 Blackout cycling reliability are the priorities. Choose Hodgdon H110 if maximum velocity in 44 Magnum and 357 Magnum with jacketed bullets at all-maximum loading is the exclusive application. Choose Vihtavuori N110 if single-base chemistry with substantially better temperature stability is the priority and premium price is acceptable.
Editor’s note: Published load data and manufacturer specifications are the starting point – not the final word. Field experience from reloaders who have actually worked with this powder is the most reliable guide to what it does in practice. If you have used IMR 4227, share your results in the comments.
Editorial note: Originally published 2026, revised May 2026. The revision added the burn rate positioning table comparing IMR 4227 to adjacent powders by key characteristic, expanded the single-base chemistry benefits section with the specific suppressor carbon accumulation mechanism, corrected the temperature sensitivity figure (original stated 1.17 fps/°F – the more accurate range is 1.1-1.3 fps/°F), added the 300 Blackout subsonic cold-weather cycling verification protocol, added the Vihtavuori N110 comparison as the closest single-base alternative, extended the bullet and primer tables with full internal links, and added three community data disclaimer blocks in the correct blockquote format.
