Vihtavuori N133 is a legendary single-base rifle powder that has earned a reputation as the gold standard for short-range benchrest shooting. Originally developed for 5.56 NATO military applications, it evolved into a premier competition propellant known for its extreme consistency and ease of tuning. It is arguably the most successful powder in the history of 100 and 200-meter benchrest competitions, having been used to set more world records than nearly any other powder in its class.
The 6mm PPC and Benchrest Dominance
The primary claim to fame for N133 is its unparalleled synergy with the 6mm PPC. In the world of precision shooting, the combination of Lapua .220 Russian brass and Vihtavuori N133 is considered the “magic formula.”
- Ease of Tuning: N133 is famous for having a “wide window” of accuracy. While other powders may require constant adjustment as temperatures rise during a match, N133 often stays in tune all day, allowing competitors to focus on the wind rather than their load data.
- Consistency: Benchrest shooters rely on N133 because of its lot-to-lot uniformity. This reliability is critical when matches are decided by thousandths of an inch.
Versatility in Small and Medium Calibers
Beyond the competition circuit, N133 is an outstanding multipurpose powder for a variety of small-bore and intermediate cartridges. Its medium-fast burn rate makes it ideal for:
- .223 Remington / 5.56 NATO: It is a top-tier choice for AR-15 shooters and bolt-action varmint hunters using lighter bullets, typically in the 45gr to 55gr range. It delivers high velocities and exceptional “bug hole” accuracy.
- .222 Remington: Many handloaders prefer N133 for the “Triple Deuce” to achieve maximum precision for varmint control.
- Large Straight-Wall Cases: Surprisingly, N133 also finds utility in large-bore cartridges like the .45-70 Government, where a relatively fast-burning rifle powder is needed to efficiently push heavy projectiles in shorter barrels.
Physical Characteristics and Clean Performance
N133 is a tubular, extruded powder with very consistent grain dimensions (1.1 mm length by 0.8 mm diameter).
- Metering: The small, uniform grains allow it to flow smoothly through volumetric powder measures, which is essential for shooters who “throw” their charges at the range rather than weighing each one.
- Clean Burning: Like all Vihtavuori N100 series powders, N133 is a pure nitrocellulose propellant. It burns exceptionally clean and includes modern anti-fouling additives to prevent copper build-up in the barrel.
- Thermodynamics: Despite some misconceptions that it is a “hot” powder due to its high accuracy at top-end loads, N133 is actually a relatively cool-burning powder compared to high-energy double-base alternatives. This helps preserve barrel life during high-volume strings of fire.
Temperature Stability
One of the reasons for its dominance in competition is its excellent temperature stability. Finnish engineering ensures that N133 maintains consistent pressures and velocities across varying weather conditions. Whether you are shooting in the cool morning air or the midday heat, N133 provides a predictable point of impact, which is why it remains a staple for serious recreational shooters and champions alike.
