Originally developed for the 7.62×51 NATO M80 Ball cartridge, Vihtavuori N135 has evolved into a staple “universal” powder for reloaders seeking high accuracy and consistent performance across a vast spectrum of calibers. Positioned in the middle of Vihtavuori’s N100 single-base series, N135 is a tubular-grain propellant known for its medium burn rate, making it exceptionally versatile for everything from small-bore varmint rounds to large straight-walled cartridges.+1
Optimal Applications and Calibers
N135 is widely recognized for its “sweet spot” in performance when paired with medium-weight bullets in mid-capacity cases. It is particularly renowned for:
- .308 Winchester: It is considered one of the best powders for .308 loads utilizing bullet weights under 155 grains. When paired with a 155gr Open Tip Match (OTM) bullet, it delivers a combination of high velocity and benchrest-grade accuracy.+1
- .223 Remington / 5.56 NATO: N135 is a top-tier choice for shooters using 60gr to 77gr bullets. It is frequently cited as more accurate and cleaner-burning than many competitive domestic powders, especially in 20-inch barrels.
- Varmint and Target Rounds: It provides outstanding results in the 6mm BR Norma, 6.5mm Grendel, and .222 Remington, where consistent ignition and low standard deviations are critical for long-range precision.
- Straight-Walled Cartridges: Surprisingly versatile, N135 also performs well in large-bore, straight-walled cases such as the .45-70 Government and .458 Winchester Magnum, offering a stable pressure curve for these heavy-hitting rounds.
Physical Properties and Metering
N135 is an extruded, single-base powder with a tubular grain geometry (1.0 mm length by 0.8 mm diameter). While these are “stick” grains, they are relatively short, allowing the powder to meter more consistently through volumetric measures than the larger kernels found in slower magnum powders.
Because it is a single-base powder, N135 is inherently cleaner-burning and typically less sensitive to copper fouling than double-base alternatives. It now includes modern anti-fouling additives to further extend the time between deep barrel cleanings, making it a favorite for high-volume competitive shooters.
Burn Rate and Temperature Stability
On the relative burn rate scale, N135 sits near popular powders like Hodgdon H4895, IMR 4064, and Accurate 2520.
One of its most significant advantages is its temperature stability. Vihtavuori’s manufacturing process ensures that N135 maintains a very consistent muzzle velocity across a wide range of ambient temperatures. This reliability is vital for hunters and target shooters who need their point of impact to remain the same whether they are shooting in the heat of summer or the freezing cold of a late-season hunt.
Why Choose N135?
For the reloader, N135 represents a “one-bottle solution” for many of the most popular rifle calibers. Its reputation for world-class accuracy is backed by its frequent use in setting benchrest records. Whether you are loading M80-style ball ammo for a semi-auto platform or precision match loads for a bolt-action rifle, N135 delivers the uniformity and “premium Finnish quality” that Vihtavuori is known for.
