The Hodgdon Retumbo is a magnum extruded rifle powder specifically engineered for large-capacity, overbore cartridges that require a slow, controlled burn to achieve peak ballistic performance. As a cornerstone of the Hodgdon Extreme series, Hodgdon Retumbo was meticulously developed to provide significant velocity gains-ranging from 40-100 feet per second-over traditional magnum propellants in cartridges like the 300 Remington Ultra Magnum and the 30-378 Weatherby Magnum. Its formulation focuses on high-energy output paired with the legendary temperature stability that the Extreme line is known for, making it a premier choice for big-game hunters and long-range precision shooters who operate in varied environmental conditions. Whether stabilizing heavy projectiles in a 338 Lapua Magnum or maximizing the efficiency of the 7mm PRC, Hodgdon Retumbo delivers the consistency required for extreme-distance accuracy.
Executive Summary
- Main Application: Exceptionally large overbore cartridges with high powder-to-bore ratios.
- Key Advantage: Significant velocity increases (40-100 fps) over standard magnum powders.
- Burn Rate: Ultra-slow, specifically optimized for heavy-for-caliber bullets.
- What This Guide Covers: Physical properties, temperature stability analysis, a 4-way competitive comparison, and detailed component compatibility.
Best For: Extreme long-range shooters and hunters using massive capacity magnum cases.
Powder Description & Technical Profile
The Hodgdon Retumbo is a single-base, extruded (stick) propellant with a grain geometry designed for uniform ignition and consistent metering. The kernels are cut to a specific length to optimize case fill and burn characteristics in voluminous rifle hulls. This physical structure allows Hodgdon Retumbo to fill large cases efficiently, which promotes lower standard deviations in muzzle velocity by reducing air space within the cartridge.
Physical Properties
- Type: Extruded (Stick)
- Base: Single-Base
- Density: 101.1 lbs/ft³
- Bulk Density: 0.925 g/cc (57.7 lbs/ft³)
The Expert “Feel”
Reloaders utilizing Hodgdon Retumbo often describe its internal ballistics as a “hammer” that provides a massive but sustained push to the projectile. Unlike faster powders that may create sharp pressure spikes, Hodgdon Retumbo maintains a progressive burn throughout the length of the barrel, which is essential for reaching the high velocities required for heavy target and hunting bullets. The powder’s consistency allows users to develop loads with single-digit standard deviations (SD), which is the gold standard for long-range precision.
Pros & Cons
- Pros:
- Exceptional velocity potential in large overbore cartridges.
- Elite temperature stability across extreme weather conditions.
- High load density improves ignition consistency in large cases.
- Part of the “Extreme” line, ensuring minimal fouling and consistent performance.
- Cons:
- Granule size can cause carbon fouling in some barrels if not cleaned regularly.
- Frequent market shortages due to high demand among magnum shooters.
- Too slow for standard cartridges like the 308 Winchester or 223 Remington.
Burn Rate and Temperature Stability
The defining feature of Hodgdon Retumbo is its membership in the Hodgdon Extreme series. These powders are chemically stabilized to resist the influence of ambient temperatures, which is critical for maintaining a consistent point of impact at long range.
Burn Rate Analysis
In the relative burn rate hierarchy, Hodgdon Retumbo is classified as an “Ultra-Slow” powder. On official charts, it sits significantly slower than Hodgdon H1000 and just faster than Hodgdon US 869 or Hodgdon H50BMG. This makes it the ideal propellant for cartridges that have more volume than a 300 Winchester Magnum can typically exploit, such as the RUM series or the 30-378 Weatherby Magnum.
Temperature Sensitivity
Technical data shows that Hodgdon Retumbo exhibits very low velocity variation when temperatures swing. While standard powders can vary by as much as 1.5-2.0 fps per degree, Hodgdon Retumbo typically ranges between 0.16 and 0.5 fps per degree. This allows a hunter to develop a precision load in the heat of summer and take it into sub-zero winter conditions with total confidence in their trajectory.
Stability Table
| Powder | Velocity Change (FPS per °F) | Stability Rating |
| Hodgdon Retumbo | 0.16-0.5 | Elite |
| Hodgdon H1000 | 0.21 | Extreme |
| Alliant Reloder 22 | 1.50+ | Sensitive |
Powder Comparison
To understand the utility of Hodgdon Retumbo, it is best to compare it against its closest market rivals.
- Hodgdon H1000: Often the first choice before moving to Hodgdon Retumbo. Hodgdon H1000 is slightly faster and is the gold standard for the 300 Winchester Magnum, but Hodgdon Retumbo will typically provide 50-100 fps more velocity in larger cases like the 300 RUM.
- Alliant Reloder 26: This is a high-energy Swiss powder that can occasionally match Hodgdon Retumbo in velocity. However, Alliant Reloder 26 is significantly denser and can be more temperature-sensitive in extremely hot conditions compared to the stable Hodgdon Retumbo.
- Vihtavuori N570: A European favorite for the 338 Lapua Magnum. N570 is very similar in burn rate but features very large kernels that can be difficult to meter. Hodgdon Retumbo is often preferred for its better availability and consistent performance in the Extreme line.
- Alliant Reloder 33: Specifically designed for the 338 Lapua Magnum, RL33 is a slower spherical powder that can push velocities even higher than Hodgdon Retumbo. However, it lacks the single-base stability of Hodgdon Retumbo and can be much more sensitive to pressure spikes in high heat.
Comparison Table
| Powder | Burn Rate | Density (g/cc) | Primary Cartridges |
| Hodgdon Retumbo | Ultra Slow | 0.925 | 300 RUM, 338 Lapua Magnum, 28 Nosler |
| Hodgdon H1000 | Very Slow | 0.910 | 7mm Remington Magnum, 300 Winchester Magnum |
| Alliant Reloder 26 | Very Slow | 0.989 | 6.5 PRC, 7mm PRC, 300 Winchester Magnum |
| Vihtavuori N570 | Ultra Slow | 0.960 | 300 PRC, 338 Lapua Magnum, 30-378 Weatherby |
| Alliant Reloder 33 | Super Slow | 1.010 | 338 Lapua Magnum, 28 Nosler |
Applications and Performance
The performance profile of Hodgdon Retumbo is maximized when it is used in cartridges with “overbore” ratios, where the amount of powder is high relative to the bore diameter.
Optimal Matches
For the 300 Remington Ultra Magnum, Hodgdon Retumbo is arguably the most popular powder ever produced, especially when using 210-230 grain bullets. In the 338 Lapua Magnum, it is a top performer for those seeking consistent accuracy with 285-300 grain projectiles. It is also highly effective in the 30-378 Weatherby Magnum, where it helps achieve the blistering velocities the cartridge is famous for without dangerous pressure spikes.
Metering and Consistency
As an extruded powder, Hodgdon Retumbo features stick-like granules that are larger than those found in standard rifle powders. While it can be metered through high-end volumetric measures, most precision reloaders prefer to use electronic powder dispensers to ensure every charge is weighed to the exact tenth of a grain. This meticulousness is rewarded with incredibly low Extreme Spread (ES) numbers during long-range sessions.
Cleanliness
Because it is a member of the Extreme line, Hodgdon Retumbo is formulated to burn cleanly at its intended pressure levels. However, in very large cases, some users have noted a buildup of carbon fouling over long strings of fire. Using a high-quality bore cleaner regularly ensures that the rifle maintains its peak accuracy over the life of the barrel.
Component Compatibility and Interlinking
Cartridges and Cases
Using premium brass is vital for maintaining the safety and performance levels that Hodgdon Retumbo can generate.
| Cartridge | Recommended Brass |
| 7mm Remington Magnum | ADG |
| 7mm PRC | Hornady |
| 300 PRC | Lapua |
| 300 Remington Ultra Magnum | Remington |
| 300 Winchester Magnum | Norma |
| 6.8 Western | Winchester |
| 338 Lapua Magnum | Lapua |
Bullets
High-BC projectiles are the best partners for the high velocities provided by Hodgdon Retumbo.
| Bullet Model | Application |
| Berger VLD Hunting | Long-Range Precision Hunting |
| Hornady ELD-M | Extreme Range Match |
| Sierra MatchKing | Tactical/Target Precision |
| Nosler Partition | Heavy Game Performance |
| Barnes TTSX | Lead-Free High Velocity |
Primers
For a powder as slow-burning as Hodgdon Retumbo, Large Rifle Magnum primers are essentially mandatory to ensure consistent ignition of the massive powder column.
| Model | Type | Best Application |
| Federal GM215M | Magnum Match | Preferred for 300 RUM and 338 Lapua |
| CCI 250 | Magnum | Excellent reliability in hunting conditions |
| Winchester WLRM | Magnum | Consistent ignition for heavy hunting loads |
| Remington 9-1/2M | Magnum | Recommended for Ultra Magnum cases |
| RWS 5333 | Magnum | Premium European precision |
| Murom KVB-7M | Magnum | High-consistency training option |
| Fiocchi 616 | Magnum | Reliable budget-friendly magnum primer |
| S&B Large Rifle Magnum | Magnum | Effective for high-volume loading |
Conclusion and Expert Verdict
Hodgdon Retumbo remains one of the most important propellants in the world of high-performance shooting. Its unique ability to maximize velocity in the largest of rifle cases while remaining virtually indifferent to temperature makes it a required staple for any serious long-range reloader. While it is too slow for standard long-action cartridges, in the world of Ultra Magnums and heavy-caliber precision rifles, it has few equals.
Expert Pro Tip: When loading with Hodgdon Retumbo, pay close attention to the seating depth of your bullets. Many expert shooters have found that this powder performs best when bullets are seated relatively close to the rifling lands (often within 0.010-0.020 inches), provided the cartridge length still functions in your magazine. This minimizes the initial air gap and helps the slow-burning powder build pressure consistently, which often tightens vertical grouping at distances beyond 600 yards.
