Vihtavuori N340 is a medium-burning, single-base handgun powder widely regarded as one of the most flexible and popular propellants in the N300 series. Originally developed for 9mm Luger and shotshell loads (formerly known as 3N18), N340 has evolved into a “true multipurpose” powder that excels in a broad range of medium to high-velocity handgun applications. It is the preferred choice for reloaders who want a single, clean-burning powder capable of handling everything from standard target loads to high-intensity magnum cartridges.
Versatility and Caliber Applications
N340 occupies the middle of the burn rate scale for Vihtavuori handgun powders, sitting between the faster N330 and the slower N350. This position makes it exceptionally well-suited for high-pressure rounds and heavy bullet weights where the shooter needs more velocity than a fast-burning powder can safely provide.
- 9mm Luger: N340 is a legendary performer for the 9mm, especially with 124gr and 147gr bullets. It is often used by competitive shooters to achieve higher power factors while maintaining manageable recoil.
- .40 S&W and 10mm Auto: The progressive burn rate of N340 allows it to push heavy 180gr and 200gr bullets to impressive velocities, making it a favorite for “major power factor” loads in action shooting sports.
- .357 SIG and .38 Super: These high-intensity cartridges benefit from N340’s ability to generate high pressures smoothly, resulting in excellent accuracy and repeatable ballistics.
- Magnum Revolvers: While not as slow as dedicated magnum powders like N110, N340 is a superb choice for “medium-heavy” loads in the .357 Magnum and .44 Magnum, as well as standard pressure .45 Colt and .44 Special.
- .45 ACP: It provides a soft-shooting but high-velocity alternative for heavy 230gr bullets, often delivering better case fill than faster powders.
Physical Properties and Clean Burning
As a porous single-base powder, N340 is engineered for consistency and cleanliness:
- Grain Geometry: N340 features small, extruded tubular grains (1.0 mm length x 0.8 mm diameter). This size is identical to N320 and N350; only the porosity of the grains is adjusted to change the burn rate.
- Superior Metering: The uniform grain size allows N340 to flow exceptionally well through volumetric powder measures, ensuring high charge-to-charge weight consistency, which is vital for maintaining low standard deviations in velocity.
- Residue-Free Performance: True to the Vihtavuori reputation, N340 is famous for its clean-burning characteristics. It leaves virtually no unburned flakes or carbon residue in the barrel or action, extending the intervals between firearm cleanings and ensuring reliable function in semi-automatic pistols.
Modern Additives and Stability
N340 incorporates the latest in propellant technology to ensure safety and longevity for the firearm:
- Decoppering Agent: Vihtavuori includes an integrated decoppering additive that helps prevent the adhesion of copper jacket material to the rifling. This helps maintain accuracy during long shooting sessions and makes barrel maintenance easier.
- Temperature Insensitivity: Like the rest of the N300 series, N340 is designed to be remarkably stable across a wide temperature spectrum. Whether shooting in extreme winter cold or mid-summer heat, the muzzle velocity and point of impact remain consistent.
- Long Shelf Life: When stored in its original container under proper conditions, N340 has a minimum estimated shelf life of 10 years, making it a reliable choice for long-term supply.
Comparison to Competition
On the relative burn rate scale, N340 is often compared to Alliant Unique, Alliant Herco, and Accurate No. 5. However, it is generally considered to be cleaner-burning and more temperature-stable than many of its domestic counterparts. For shooters who demand the highest precision and a “service-pistol” feel with premium Finnish quality, N340 remains the go-to multipurpose handgun propellant.
