Vihtavuori 3N37 Smokeless Gun Powder: Competition Handgun Powder for 9mm Major, .40 S&W & Magnum Revolver Loads

Vihtavuori 3N37 is a cylindrical (tubular) handgun powder with a burn rate close to Vihtavuori N350, on the medium-fast end of Vihtavuori’s handgun powder lineup — notably faster-burning than classic big-bore magnum powders like Alliant 2400, Accurate No. 9, Hodgdon H110, and Winchester 296. It’s primarily a competition powder, developed for USPSA/IPSC practical pistol shooting and 9mm major power-factor loads, and is also used in magnum revolver cartridges.

Built for Competition and Magnum Performance

3N37 traces its roots to a powder originally developed for .22 rimfire ammunition and has been in production since the 1940s, giving Vihtavuori decades of manufacturing experience with this propellant. Its uniform cylindrical grain structure meters consistently through a powder measure, an important trait for the high-volume charge-throwing that competition and submachine-gun reloading demand.

Application Versatility

3N37 has published load data for 9mm Luger, .40 Smith & Wesson, .45 Automatic, .38 Special, .357 Magnum, .357 Maximum, .41 Remington Magnum, .44 Remington Magnum, .454 Casull, .460 S&W Magnum, and 5.7x28mm. It’s a favorite for 9mm major and other USPSA/IPSC open-division loads, while its magnum-cartridge data makes it a capable choice for big-bore revolver reloading as well.

Load Development

Always use published, manufacturer-tested load data when developing loads with 3N37. 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: Cylindrical smokeless handgun powder, medium-fast burn rate close to Vihtavuori N350, faster-burning than Alliant 2400 / Accurate No. 9 / H110 / Win296
• Manufacturer: Vihtavuori (Finland)
• Best for: 9mm Luger (major power factor), .40 S&W, .45 Automatic, .38 Special, .357 Magnum, .357 Maximum, .41 Rem Mag, .44 Rem Mag, .454 Casull, .460 S&W Magnum, 5.7x28mm
• Container sizes: 1 Lb, 4 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 3N37 in its original, sealed container in a cool, dry, well-ventilated place away from sunlight and heat sources.

Vihtavuori 3N37 For Sale, In Stock

USReloadingPowder keeps Vihtavuori 3N37 Smokeless Gun Powder in stock for competition and magnum revolver reloaders. Browse the rest of our lineup on the Vihtavuori Powders category page.

FAQs

What cartridges is 3N37 best for? It has published load data for 9mm Luger, .40 S&W, .45 Automatic, .38 Special, .357 Magnum, .357 Maximum, .41 Rem Mag, .44 Rem Mag, .454 Casull, .460 S&W Magnum, and 5.7x28mm, and is popular for 9mm major power-factor competition loads.

Is 3N37 a magnum revolver powder? It’s primarily a competition powder for USPSA/IPSC practical pistol shooting, though its published data covers several magnum revolver cartridges as well.

How does its burn rate compare to other handgun powders? It’s medium-fast, close to Vihtavuori N350, and notably faster-burning than classic big-bore magnum powders like Alliant 2400, Accurate No. 9, H110, and Winchester 296.

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.