Vihtavuori N170 Smokeless Gun Powder: Ultra-Slow-Burning Magnum Rifle Powder for .300 Weatherby, .300 RUM & Big-Case Cartridges

Vihtavuori N170 is a single-base N100-series rifle powder and the slowest-burning member of that series (not counting the specialty 20N29 and 24N41) — in fact, one of the slowest canister-grade rifle powders available from any manufacturer. On combined burn-rate references it sits just behind Alliant Reloder 25 and Vihtavuori N565, and burns noticeably faster than powders like Hodgdon H1000, Retumbo, and Reloder 33. It’s built for very large-capacity cartridges that need a lot of slow-burning powder to fill the case and generate top velocity.

Built for Big-Case, Big-Magnum Performance

Like all Vihtavuori rifle powders, N170 uses a cylindrical, single-perforated extruded grain — 1.7 mm long and 1.1 mm in diameter, a relatively large grain size that suits its slow burn rate. Vihtavuori’s production process controls the full chain from nitrocellulose manufacture to final bottling, giving consistent lot-to-lot performance that reloaders have relied on for decades.

Application Versatility

N170 has official published load data for .22 Creedmoor, .25-06 Remington, 6.5 PRC, 6.5×55, 6.5-284 Norma, 6.8 Western, .270 Weatherby Magnum, 7mm Remington Magnum, 7mm PRC, 7mm Remington Ultra Magnum, .300 WSM, .300 Norma Magnum, .300 PRC, .300 Winchester Magnum, .300 Weatherby Magnum, .300 Lapua Magnum, .300 Remington Ultra Magnum, .30-378 Weatherby Magnum, .338 Lapua Magnum, .375 CheyTac, and .50 BMG. It’s a favorite among long-range big-game hunters and target shooters running large-capacity magnum cases where a very slow-burning powder is needed to reach top velocities. If you’re loading a slightly smaller-capacity magnum case and want a comparably slow-burning option, Vihtavuori N560 is worth comparing.

Load Development

Always use published, manufacturer-tested load data when developing loads with N170. Start at the published minimum charge and work up in small increments, weigh every charge on a calibrated scale, and chronograph each string to track velocity consistency. Keep primer brand, bullet lot, and brass lot constant during development, watch for pressure signs, and document charge weight, seating depth, primer, and chronograph results so successful loads can be reproduced.

Quick Specs

• Type: Single-base extruded rifle powder, N100 series, cylindrical single-perforated grain (1.7mm length x 1.1mm diameter), slowest-burning powder in the N100 series
• Manufacturer: Vihtavuori (Finland)
• Best for: .300 Weatherby Magnum, .300 Remington Ultra Magnum, 7mm Remington Magnum, .338 Lapua Magnum, .300 Norma Magnum, .300 PRC, and other large-capacity magnum cartridges
• Container size: 1 Lb

Safety Reminders

Before loading, review a few important guidelines. Never exceed the loads displayed in your reloading guide. Never mix two powders together, regardless of type, brand, or source. Never substitute smokeless powder for Black Powder or any Black Powder substitute. Store N170 in its original, sealed container in a cool, dry, well-ventilated place away from sunlight and heat sources.

Vihtavuori N170 For Sale, In Stock

USReloadingPowder keeps Vihtavuori N170 Smokeless Gun Powder in stock for big-case magnum rifle reloaders. Browse the rest of our lineup on the Vihtavuori Powders category page.

FAQs

What cartridges is N170 best for? It has official published load data for large-capacity magnum cartridges including .300 Weatherby Magnum, .300 Remington Ultra Magnum, 7mm Remington Magnum, .300 Norma Magnum, .300 PRC, .338 Lapua Magnum, and .50 BMG, among others.

Is N170 really the slowest powder in the N100 series? Yes — Vihtavuori positions it as the slowest-burning N100-series powder (aside from the specialty 20N29 and 24N41) and one of the slowest canister-grade rifle powders available from any manufacturer.

How does its burn rate compare to other slow magnum powders? It sits close to Alliant Reloder 25 and Vihtavuori N565, and burns noticeably faster than powders like Hodgdon H1000, Retumbo, and Reloder 33.

How should I store it long-term? Keep it sealed in its original container, stored in a cool, dry, ventilated location away from heat and sunlight. Proper storage keeps powder stable for years.