Vihtavuori N540 (454 g) is a versatile, high-energy rifle propellant engineered for medium-calibre cartridges, delivering outstanding performance from .223/5.56 through .308 Winchester and .30-06 Springfield, particularly with heavier bullets. As part of the N500 series, it incorporates added nitroglycerine to provide more energy than traditional N100 powders, enabling reloaders to achieve roughly 30–40 m/s higher velocities at comparable pressures when greater muzzle speed or loading density is desired. Its clean, consistent burn promotes excellent accuracy for both hunting and target applications, while the uniform 1.0 × 1.0 mm grain geometry ensures reliable, smooth metering for easy measuring and loading—making N540 a dependable, precision-focused choice for refining mid-calibre loads.