Vihtavuori N555 represents the pinnacle of modern propellant engineering, specifically developed to dominate the high-performance precision rifle market. As a recent addition to the legendary N500 series, Vihtavuori N555 was engineered from the ground up to address the specific needs of shooters using 6.5 Creedmoor and similar mid-sized cartridges. While the legacy N500 series was known for raw energy, Vihtavuori N555 marks a significant evolution by combining that characteristic high velocity with world-class temperature stability and integrated anti-fouling technology.
In the competitive landscape of long-range shooting, where a few feet per second can be the difference between a hit and a miss at 1000 yards, Vihtavuori N555 offers a unique competitive edge. It provides the sustained energy of a double-base powder while maintaining the consistency and barrel-friendly nature typically associated with single-base powders. This propellant is not merely a modification of existing formulas; it is a specialized solution for the modern marksman who demands perfection in every grain.
Executive Summary
- Main Application: Precision Rifle Series (PRS) competition and long-range hunting.
- Key Advantage: Optimized burn rate for 6.5 Creedmoor combined with extreme thermal stability.
- Burn Rate: Medium-slow, sitting precisely between Hodgdon H4350 and Alliant Reloder 16.
- What This Guide Covers: Detailed analysis of the N500 series chemistry, physical kernel properties, comparative stability testing, and optimized component matching for 6.5 Creedmoor, 260 Remington, and 7mm-08 Remington.
Best For: Serious competitive shooters and precision hunters who require maximum muzzle velocity without sacrificing the thermal immunity required for multi-day matches or high-altitude hunts.
Powder Description & Technical Profile
Vihtavuori N555 is an extruded powder featuring a highly specialized chemical composition. As part of the N500 high-energy series, Vihtavuori N555 is technically a double-base powder. This means that during the manufacturing process, nitroglycerin is added to the nitrocellulose base. This infusion increases the specific energy of the propellant, allowing Vihtavuori N555 to produce higher velocities at the same chamber pressures compared to traditional single-base powders.
However, what sets Vihtavuori N555 apart from earlier N500 propellants is the inclusion of advanced additives designed to minimize the traditional drawbacks of double-base propellants. Historically, high-energy powders were prone to increased barrel wear due to higher flame temperatures. Vihtavuori N555 incorporates a specific decoppering agent that scours the bore during the shot, reducing copper buildup and protecting the throat. Furthermore, the grain geometry of Vihtavuori N555 is a small-cut stick, meticulously shaped to ensure high load density and excellent flow.
The expert “feel” of Vihtavuori N555 is characterized by its progressive pressure curve. Unlike some propellants that exhibit a sharp, violent spike, Vihtavuori N555 provides a sustained push against the bullet. This leads to high muzzle velocities and, more importantly, very low standard deviations (SD) in velocity. For the reloader, this translates to predictable behavior even when approaching the limits of overpressure.
Pros & Cons
- Pro: Specifically tuned for 6.5 Creedmoor, providing exceptional case fill and velocity.
- Pro: Industry-leading temperature stability for a high-energy propellant.
- Pro: Integrated decoppering agent extends accuracy intervals between cleanings.
- Pro: High bulk density allows for maximum energy without excessive load compression.
- Con: As a high-energy powder, it generates more heat than the N100 series.
- Con: Premium pricing reflects its status as a top-tier competition propellant.
Technical Characteristics
The physical properties of Vihtavuori N555 reflect the precision manufacturing standards of the Finnish facility. Every batch is tested to ensure that burn rates remain within a tight 1 percent tolerance.
| Property | Specification |
| Bulk Density (g/l) | 900-920 |
| Burn Rate Category | Medium-Slow Rifle |
| Grain Shape | Small Cylindrical Stick |
| Base | Double-Base (Nitroglycerin Infused) |
| Coating | Graphite with Decoppering Additive |
Temperature Stability & Burn Rate Analysis
A primary concern for precision shooters is how a powder reacts to the environment. Vihtavuori N555 was specifically designed to compete with the “Extreme” line of propellants from other manufacturers. In comparative testing across a temperature range of -15 to 110 degrees Fahrenheit, Vihtavuori N555 showed a velocity variance of only 0.4-0.6 FPS per degree. This level of thermal immunity is remarkable for a double-base powder.
This stability means that a load developed in a cool spring morning will hold its elevation at a match in the midday summer heat. For hunters, it ensures that a zero confirmed in the valley remains valid on a frozen mountain peak. The burn rate of Vihtavuori N555 is perfectly situated for modern “short-magnum” and medium cartridges that utilize heavy-for-caliber projectiles with high ballistic coefficients.
Stability Table
| Powder | Stability Rating | Sensitivity (FPS Variation) |
| Vihtavuori N555 | Ultra-Stable | 0.4-0.6 FPS per Degree |
| Hodgdon H4350 | Ultra-Stable | 0.5-0.7 FPS per Degree |
| Alliant Reloder 17 | Moderate | 1.4-1.9 FPS per Degree |
| Vihtavuori N550 | Moderate | 1.6-2.1 FPS per Degree |
Powder Comparison
To understand the market position of Vihtavuori N555, one must compare it against the dominant powders in the 6.5 Creedmoor and 308 Winchester class.
| Powder | Burn Rate | Density | Primary Cartridges |
| Vihtavuori N150 | Faster | 0.910 | 308 Winchester, 6mm BR |
| Hodgdon H4350 | Slightly Faster | 0.890 | 6.5 Creedmoor, 243 Winchester |
| Vihtavuori N555 | Subject | 0.910 | 6.5 Creedmoor, 260 Remington |
| Alliant Reloder 16 | Slightly Slower | 0.930 | 6.5 Creedmoor, 7mm-08 Remington |
| Vihtavuori N560 | Slower | 0.960 | 6.5 PRC, 270 Winchester |
Performance, Metering & Equipment
Despite being an extruded powder, the kernel size of Vihtavuori N555 is small and uniform. This facilitates exceptional flow through volumetric powder measures. In testing with high-end mechanical throws, Vihtavuori N555 consistently holds tolerances within +/- 0.1 grains. For those loading ammunition for the highest levels of competition, electronic precision is still recommended to ensure the absolute minimum velocity spread.
Recommended Equipment
- RCBS Chargemaster Lite: An excellent match for the flow characteristics of Vihtavuori N555.
- Lyman Gen6 Compact Powder System: Ideal for small reloading benches while maintaining high accuracy.
- Frankford Arsenal Powder Trickler: Used to hand-finish charges to the exact kernel for 1000-yard loads.
- Area 419 Powder Cup and Drop Tube Set: Essential for managing high load densities and settling kernels in the case neck.
Fouling with Vihtavuori N555 is notably different from legacy powders. The decoppering agent creates a chemical environment where copper residue is less likely to bond with the steel of the barrel. Shooters often report that after a 100-round string of fire, the bore appears significantly cleaner, and accuracy remains consistent from shot 1 to shot 100. This makes it an ideal choice for high-volume matches where cleaning during the day is not an option.
Recommended Cartridges and Applications
While Vihtavuori N555 was designed with 6.5 Creedmoor in mind, its burn rate and energy density make it highly effective in a variety of modern cartridges.
| Cartridge | Primary Application |
| 6.5 Creedmoor | Precision Rifle Competition / PRS |
| 260 Remington | Tactical Long Range Shooting |
| 6.5×55 SE | Modern Match & Traditional Hunting |
| 7mm-08 Remington | Short-Action Big Game Hunting |
| 284 Winchester | F-Class Open Competition |
| 308 Winchester | Heavy-Projectile Long Range Target |
| 6mm Creedmoor | High Velocity PRS / Varmint |
Bullets
Vihtavuori N555 performs at its peak when pushing bullets with high sectional density and high ballistic coefficients. The sustained energy release is ideal for projectiles that stay in the bore longer.
| Bullet Manufacturer | Model | Recommended Weight |
| Lapua | Scenar-L | 136-175 Grains |
| Berger Bullets | Hybrid Target | 140-153 Grains |
| Hornady | ELD Match | 140-147 Grains |
| Sierra Bullets | MatchKing | 142-150 Grains |
| Nosler | AccuBond | 140-160 Grains |
Primers
Igniting a nitroglycerin-infused propellant like Vihtavuori N555 requires consistent, high-energy ignition. The following primers have shown the best results in producing low Standard Deviations (SD) with this powder.
- CCI BR-2 Large Rifle Bench Rest: The preferred choice for 6.5 Creedmoor in large-primer brass.
- Federal Gold Medal Large Rifle Match: Known for ultra-soft cups and incredibly consistent ignition.
- CCI No. 200 Large Rifle: A robust standard choice for hunting load development.
- Remington No. 9-1/2 Large Rifle: Reliable for standard medium-bore cases.
- Winchester Large Rifle: Provides a slightly hotter flame that helps in cold-weather combustion.
- Murom Large Rifle: Highly respected international primer for high-volume competition.
- RWS 5333 Large Rifle Magnum: Recommended for maximized loads in larger cases like the 284 Winchester.
- CCI No. 450 Small Rifle Magnum: Essential for precision small-primer 6.5 Creedmoor brass.
- Federal Gold Medal AR Small Rifle: Best for small-bore precision rifles using N555.
Expert Verdict
Vihtavuori N555 has quickly ascended to the top of the propellant hierarchy for a reason. By addressing the historical temperature sensitivity issues of high-energy powders while maintaining the velocity gains that made the N500 series famous, Vihtavuori has created a near-perfect product for the modern marksman. Whether you are seeking to stay supersonic past 1200 yards in a PRS match or ensure a clean, one-shot kill on a late-season mountain hunt, Vihtavuori N555 provides the technical reliability and raw performance required for success.
The inclusion of decoppering agents and the focus on kernel uniformity demonstrate a deep understanding of what the reloader needs: accuracy, consistency, and barrel longevity. While it is a specialized powder, its versatility across the 6mm to 7mm caliber range makes it a must-have on any serious reloading bench.
Expert Pro Tip: When working with Vihtavuori N555 in the 6.5 Creedmoor, focus on load density. This powder performs exceptionally well at high case fill percentages (95-100%). If your accuracy node is slightly below this, consider using a bullet seating die to slightly increase the jump to the lands. This can often help stabilize the internal pressure and lower your Extreme Spread (ES) without requiring more powder. Always monitor for early signs of overpressure such as slight primer flattening or stiff bolt lift when pushing for maximum load density.
