Published: 2026 | Last updated: May 2026
IMR 7828 is a slow-burning, single-base long-cut extruded powder – the traditional long-grain version of a magnum rifle propellant that has been in the IMR lineup for decades. It occupies the same burn rate position as IMR 7828 SSC, with which it shares the same chemical formulation. The only difference between them is grain length: IMR 7828 uses long cylindrical kernels; IMR 7828 SSC uses super-short-cut kernels with the same chemistry.
This article covers IMR 7828 – the long-cut version. Before proceeding: for most loading applications, IMR 7828 SSC is the better practical choice. The SSC version meters substantially more consistently (±0.1-0.2 grain vs ±0.4-0.6 grain variance), packs approximately 4% more efficiently in the case, and produces identical pressure and velocity at the same charge weight under the same conditions. If you have a choice between the two, SSC is almost always preferable. IMR 7828 long-cut is documented here because it remains in production and available, and reloaders who have it should understand its properties and appropriate use.
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 7828 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 7828 is a single-base, long-cut cylindrical extruded powder. The single-base formulation – nitrocellulose without nitroglycerin – produces the clean burning and moderate temperature stability characteristics of single-base chemistry. The grain geometry is traditional large-stick extruded format.
The long cylindrical grain geometry is the defining practical limitation of IMR 7828 at the loading bench. Each kernel is significantly longer and larger in diameter than short-cut or ball powder alternatives. These large sticks:
- Bridge across measure drum apertures during metering, preventing smooth flow
- Shear at the drum edge during the measure cycle, producing broken grains of variable size that fill inconsistently
- Produce charge-to-charge variance of 0.4-0.6 grains in standard volumetric measures – a level that requires hand-weighing or auto-dispensing for any precision application
The internal ballistics characteristics are the same as IMR 7828 SSC: a progressive pressure curve that builds slowly and sustains through the long bore of a 24-26 inch magnum barrel, producing excellent velocity from heavy bullets in large-capacity cases.
Bulk density is 0.880-0.910 g/cc – somewhat lower than the SSC version’s 0.945 g/cc. This lower packing density means slightly lower maximum charge weight at any given case fill percentage compared to the SSC. It also means case fill in 7mm Remington Magnum and 300 Winchester Magnum at working charge weights is adequate (92-97%) but not as efficient as the SSC version.
Strengths:
- Identical chemistry to IMR 7828 SSC – same temperature stability, same pressure profile, same velocity at equivalent charge weights
- Deep published data library from decades in North American manuals – virtually every major magnum cartridge is covered
- Progressive pressure curve sustains velocity development through 24-26 inch magnum barrels effectively
- Single-base clean burning – less carbon residue than double-base alternatives at equivalent pressures
- Long shelf life from single-base chemical stability
Limitations:
- Large grain geometry produces 0.4-0.6 grain volumetric metering variance – hand-weighing or auto-dispensing required for any precision or hunting application
- Temperature sensitivity of approximately 1.3-1.4 fps/°F – the same as IMR 7828 SSC and substantially more sensitive than Extreme or Enduron alternatives
- SSC is better in every practical dimension – unless specifically unavailable, SSC should be used instead
- Lower packing density than SSC – approximately 4% less efficient case fill at the same charge weight
Technical Characteristics
| Property | Specification |
|---|---|
| Manufacturer | IMR (Hodgdon Powder Company) |
| Type | Single-Base Long-Cut Extruded |
| Bulk Density (g/cc) | 0.880 – 0.910 |
| Grain Shape | Long Cylindrical |
| Coating | Graphite and Stabilizers |
| Burn Rate Category | Slow Rifle (Magnum) |
| Temperature Sensitivity | ~1.3-1.4 fps / °F |
| vs. IMR 7828 SSC | Same chemistry, longer grain, less efficient |
IMR 7828 vs. IMR 7828 SSC – The Critical Comparison
This comparison deserves its own section because it defines the most important practical decision for any reloader considering IMR 7828.
| Property | IMR 7828 (Long-Cut) | IMR 7828 SSC |
|---|---|---|
| Chemistry | Single-base | Single-base (identical) |
| Temperature sensitivity | ~1.3-1.4 fps/°F | ~1.3-1.4 fps/°F |
| Bulk density | 0.880-0.910 g/cc | ~0.945 g/cc |
| Case fill efficiency | Reference | ~4% better |
| Metering variance | 0.4-0.6 grain | 0.1-0.2 grain |
| Metering method | Hand-weigh required | Quality measure adequate |
| Performance at same charge | Identical | Identical |
The verdict: IMR 7828 SSC is objectively better in practical loading use across every relevant metric while delivering identical ballistic performance at the same charge weight. The long-cut version is only the appropriate choice when SSC is unavailable.
One important note for reloaders switching between the two versions: the maximum charge weights published in IMR data are slightly different between the long-cut and SSC versions for the same cartridge and bullet combination. This reflects the different packing behavior – the SSC’s more efficient packing allows slightly different charge weights to reach the same pressure. Do not apply IMR 7828 SSC charge weights to IMR 7828 long-cut or vice versa without verification from each powder’s own published data.
Temperature Stability and Burn Rate Context
IMR 7828 sits in the slow-magnum burn rate position between Hodgdon H4831SC (slightly faster) and Hodgdon H1000 (slightly slower). The burn rate position is identical to IMR 7828 SSC – they are the same chemistry.
Temperature sensitivity of 1.3-1.4 fps per degree Fahrenheit places it in the middle of the slow-magnum spectrum – better than double-base alternatives like Alliant Reloder 22 (1.6-1.8 fps/°F), significantly worse than the Extreme series (Hodgdon H1000 at 0.21 fps/°F) and Enduron alternatives (IMR 4955 Enduron at <0.5 fps/°F).
The practical protocol is identical to IMR 7828 SSC: develop maximum charge at the highest field temperature you will encounter. For a 300 Winchester Magnum hunter who develops loads at 80°F and hunts at 15°F, the 65°F temperature drop produces approximately 85-90 fps velocity reduction – with corresponding drop chart implications at extended ranges.
Burn Rate Comparison and Competing Powders
| Powder | Type | Density (g/cc) | Key Character |
|---|---|---|---|
| Hodgdon H4831SC | Single-Base Extruded | 0.875 | Slightly Faster – Extreme stability |
| Alliant Reloder 22 | Double-Base Extruded | 0.930 | Similar – higher velocity, less stable |
| IMR 7828 SSC | Single-Base Short-Cut | 0.945 | Same chemistry, better metering |
| IMR 7828 | Single-Base Long-Cut | 0.890 | Reference – traditional long-grain |
| Hodgdon H1000 | Single-Base Extruded | 0.910 | Slightly Slower – Extreme stability |
| IMR 4955 Enduron | Single-Base Short-Cut | 0.920 | Similar – Enduron stability |
| Norma MRP | Single-Base Extruded | 0.910 | Similar – European single-base |
vs. IMR 7828 SSC: Covered in the dedicated comparison section. SSC is better in all practical dimensions.
vs. Hodgdon H4831SC: H4831SC belongs to the Extreme series with approximately 0.3 fps/°F stability – substantially better than IMR 7828’s 1.3-1.4 fps/°F. H4831SC’s short-cut geometry also meters significantly better than IMR 7828’s long-grain format. For year-round hunting where seasonal consistency matters and metering convenience is needed, H4831SC is the superior choice in most practical respects.
vs. Alliant Reloder 22: Reloder 22 is double-base and produces higher velocity from nitroglycerin energy content. It is more temperature sensitive (1.6-1.8 fps/°F) than IMR 7828 (1.3-1.4 fps/°F). IMR 7828 produces less velocity but is marginally more stable and burns cleaner from single-base chemistry. For maximum velocity in 7mm Remington Magnum and 300 Winchester Magnum with a temperature protocol, Reloder 22 is the double-base choice. For single-base cleanliness and slightly better stability, IMR 7828 is appropriate.
vs. Hodgdon H1000: H1000 is an Extreme series powder at 0.21 fps/°F – substantially more stable. It produces somewhat less velocity from single-base chemistry. For year-round precision hunting and competition, H1000 is the more seasonally practical choice.
Recommended Cartridges and Applications
IMR 7828 serves the same cartridge range as IMR 7828 SSC – the applications are determined by the burn rate, not the grain length.
| Cartridge | Bullet Weight Range | Notes |
|---|---|---|
| 7mm Remington Magnum | 154-195 gr | Primary application |
| 300 Winchester Magnum | 165-220 gr | Standard to heavy hunting |
| 270 Winchester | 140-160 gr | Heavy-bullet maximum velocity |
| 270 WSM | 140-160 gr | Short-action magnum |
| 7mm WSM | 154-175 gr | Short-action magnum |
| 300 WSM | 165-200 gr | Short-action magnum |
| 300 Weatherby Magnum | 165-200 gr | Standard Weatherby loads |
| 338 Winchester Magnum | 200-250 gr | Standard hunting loads |
| 6.5-284 Norma | 130-156 gr | Long-range loads |
Practical Loading with IMR 7828 Long-Cut
Because the long-grain geometry makes volumetric metering inadequate for precision loading, IMR 7828 loading requires a different workflow than most powders in this guide:
For single-stage precision or hunting loads: Use a volumetric measure to throw slightly under target weight, then hand-trickle to exact weight with a Frankford Arsenal Powder Trickler and high-resolution scale like the RCBS MatchMaster or Lyman Gen 6 Compact. This workflow eliminates the volumetric variance problem entirely.
For auto-dispenser loading: The RCBS ChargeMaster Supreme and Hornady Auto-Charge Pro handle large-stick extruded powders with weight-based dispensing that bypasses the volumetric variance issue. The long sticks do trickle somewhat less smoothly than short-cut alternatives, so dispense time per charge may be longer.
The long drop tube technique is specifically important with IMR 7828 long-cut. At near-maximum charge weights in 300 Winchester Magnum and 7mm Remington Magnum, the long sticks settle more consistently through a 6-10 inch drop tube than through a standard short funnel, reducing compressed load inconsistency.
Bullets
IMR 7828 is suited to the same heavy, high-BC projectiles as IMR 7828 SSC.
| Brand | Model | Weight | Cartridge | Application |
|---|---|---|---|---|
| Berger | Hybrid Target | 168-195 gr | 7mm Rem Mag / 300 Win Mag | ELR Competition |
| Hornady | ELD-X | 162-195 gr | 7mm Rem Mag / 300 Win Mag | Long-Range Hunting |
| Hornady | ELD-M | 168-195 gr | 7mm Rem Mag / 300 Win Mag | Long-Range Match |
| Nosler | AccuBond | 160-200 gr | 7mm Rem Mag / 300 Win Mag | Bonded Hunting |
| Nosler | Partition | 160-200 gr | 7mm Rem Mag / 300 Win Mag | Classic Big Game |
| Sierra | MatchKing | 175-220 gr | 7mm Rem Mag / 300 Win Mag | Competition |
| Barnes | LRX | 145-175 gr | 7mm Rem Mag / 270 Win | Lead-Free Long Range |
| Barnes | TTSX | 150-180 gr | 300 Win Mag / 7mm Rem Mag | Lead-Free Hunting |
| Federal | Trophy Bonded | 165-200 gr | 300 Win Mag | Premium Hunting |
| Lapua | Scenar | 170-185 gr | 300 Win Mag | Competition Match |
Have you loaded IMR 7828? Your practical data on charge weights, accuracy nodes, or metering approach helps other reloaders more than any spec sheet. Leave a comment below.
Primers
IMR 7828 shares the same primer requirements as IMR 7828 SSC – large rifle magnum primers for all primary applications due to the slow-burning, large powder column in large-capacity cases.
| Primer | Type | Application |
|---|---|---|
| CCI 250 | Large Rifle Magnum | General magnum standard |
| Federal GM215M | Large Rifle Magnum Match | Competition precision |
| Winchester WLRM | Large Rifle Magnum | Hunting and match loads |
| Remington 9-1/2M | Large Rifle Magnum | Standard magnum hunting |
| Federal 215 | Large Rifle Magnum | Maximum ignition large cases |
| CCI BR-2 | Large Rifle Benchrest | Competition loads |
| Fiocchi Large Rifle Magnum | Large Rifle Magnum | Consistent European alternative |
| RWS 5337 | Large Rifle Magnum | Premium European precision option |
Reloading Safety Notes
All charge weights must come from current published IMR/Hodgdon load data for IMR 7828 (long-cut) specifically. Do not use IMR 7828 SSC charge weights for the long-cut version – the different packing density produces different charge weight maximums for the same cartridge. Verify from each version’s own data.
Develop maximum charge at the highest field temperature. The 1.3-1.4 fps/°F sensitivity produces approximately 85-90 fps velocity variation over a 65°F seasonal hunting swing, and corresponding pressure variation. Loads validated at summer temperatures are safe year-round; loads validated at cool temperatures may produce elevated pressure in summer heat.
Start 10% below the listed maximum and work up in 0.3-grain increments. With large-grain extruded powders, use a long drop tube for near-maximum charges to ensure consistent kernel settling before bullet seating.
Hand-weigh or auto-dispense every charge. The 0.4-0.6 grain volumetric variance from standard measures is not acceptable for any application requiring consistency. This is not optional.
See the overpressure in reloading guide for systematic pressure sign identification.
FAQ
Should I use IMR 7828 or IMR 7828 SSC?
IMR 7828 SSC in almost every case. The SSC version has better metering, better packing efficiency, identical ballistic performance at the same charge weight, and no trade-offs. Use IMR 7828 long-cut only when SSC is not available. Note that the two versions have slightly different maximum charge weights for the same cartridge – use each version’s own published data.
Can I use H4350 charge weights for IMR 7828?
No. Hodgdon H4350 burns at a significantly different rate than IMR 7828 – H4350 is medium-slow, IMR 7828 is slow-magnum. They are in completely different burn rate categories. Do not cross-reference charge weights.
Is IMR 7828 still worth using now that SSC is available?
If you have a supply of IMR 7828 long-cut and have verified loads developed from its own data, there is no functional reason to switch. The ballistic performance at the same charge weight is identical. The practical difference is only in metering convenience – which the auto-dispenser or hand-weigh workflow already addresses.
Conclusion
IMR 7828 is a capable slow-magnum powder that has served large-capacity rifle cartridges reliably for decades. Its single-base chemistry produces clean, consistent burning across its application range. The long grain geometry is the practical limitation that IMR 7828 SSC directly addresses – when SSC is available, use it instead. When the long-cut version is what you have, hand-weighing or auto-dispensing every charge is the straightforward solution.
Choose IMR 7828 SSC over this powder whenever both are available. Choose IMR 7828 (long-cut) when SSC is unavailable and you have existing load data for it. Choose Hodgdon H1000 if Extreme series year-round stability is the priority. Choose IMR 4955 Enduron if Enduron temperature stability and decoppering chemistry are the modern alternative to this burn rate position.
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 7828, share your results in the comments.
Editorial note: Originally published 2026, revised May 2026. The revision added the explicit IMR 7828 vs. IMR 7828 SSC comparison table establishing that SSC is objectively better in practical use, added the note that charge weights differ between the long-cut and SSC versions, added the dedicated loading workflow section for managing the long-grain metering limitation, clarified the H4350 cross-reference FAQ to prevent a common but potentially dangerous confusion between very different burn rate classes, extended the bullet and primer tables with full internal links, and added three community data disclaimer blocks in the correct blockquote format.
