Vihtavuori N555 reloading powder

We put the new N555 smokeless reloading powder from Vihtavuori to the test... find out how it performed here!

Vihtavuori provide superb online reloading data, responsive for most cartridges

credit: Archant

Vihtavuori’s new N555 smokeless rifle powder has been designed for mid-sized precision rifle cartridges such as 6mm Creedmoor, 6.5 Creedmoor, .284 Winchester, .260 Remington, 6.5x55 and .30-06 Springfield. With a burn rate nestled between high-energy N550 and single-based N160 powders, it hopes to fill the gap left somewhat vacant to us reloaders by the loss of popular US powders (for me personally, H4350, which I used extensively for .260 Rem, and also the Creedmoor to a smaller extent).

Vihtavuori are assuring “the most temperature-stable reloading powder in its class,” and I tend to agree, as although we UK shooters suffer less from extremes of temperature, this spring/summer has seen relatively broad day to day variation with 5 to 35°C temperature shifts from early mornings into the heat of the day, when ammunition left carelessly in the sun can show pressure extremes.

I’m pleased to say, even with stout N555s, reloads have never caused undue concern or significant variation. Most of my range work consisted of the usual ladder testing at 100m at about 10°C air temp with the final adventure, in my .260 Rem, being at 1,050m with sub-MOA variation on a hot 30°C day in light winds.

Muzzle velocities were delightfully close to those suggested by Vihtavuori’s own data, which I found pleasing with easily observed specific accuracy nodes, each spanning over a 1gr window. Saying that, short kernels measured well didn’t bounce in the scale pan and sub-0.1gr was available easily with sub-0.3gr available from volumetric measurement alone, thanks to the relatively bulky powder showing 900g density.

Vihtavuori have extensive reloading data available online and are one of the few to show specific barrel length variance for the 6.5x55, which is particularly useful to those considering older military rifles versus new SKAN variants. N555 is ideal in all 6.5 Creedmoor bullet weights, the cartridge for which it was primarily developed but like all powders it has a broad reach across bullet weights and case volumes specific to each chambering.

It was slightly on the fast side for .260, but I found it gave excellent results on paper and distant targets with little experimentation required for the 130 gr Sierra TMK bullet, with my next project being to experiment with 143 and 147gr Hornady ELD M/X variants.

An anti-fouling agent minimizes barrel fouling with “unmatched lot-to-lot consistency” to eliminate expensive range time redeveloping of your preferred loads. The energy content of N555 is 3.700 J/g which, given Viht’s own High Energy Tagline, is the lowest of all the Double Based 5** series powders but burn rate and consistency is the key aspect for reloaders tuning their ammo.

N555 is available in 1lb, 1kg and larger volumes, so If you seek a great powder for the mid-range 6.5s, now you have it, it’s a powder I will now be using as a first port of call when developing new loads for this kind of calibre.

I can work with that kind of 100 metre performance and sub 20 fps extreme spreads with good temperature stability