The Sellier & Bellot 4,4 SPM Small Pistol Magnum Boxer Primers (MPN V360247) deliver high-brisance ignition engineered for high-pressure handgun ammunition and select small-capacity rifle cartridges. Manufactured with a 4.4 mm diameter (~0.175 in), these Boxer primers feature a heavy-duty cup construction designed to withstand elevated magnum chamber pressures without flowing or piercing. The non-corrosive, non-mercuric chemical priming compound produces a hotter, longer flame duration than standard small pistol primers, ensuring complete and reliable combustion of slow-burning spherical and ball powders across varied hunting and shooting conditions.

Key Features

• Magnum Priming Compound: Non-corrosive, non-mercuric chemical formulation delivers increased brisance and extended flame duration to ignite dense magnum propellant charges cleanly while preventing barrel erosion.
• Reinforced Cup Construction: Manufactured with calibrated cup depth and thickness to handle elevated magnum pressures without cup piercing or primer pocket leakage.
• Uniform Seating Dimensions: Precision 4.4 mm external diameter ensures consistent mechanical sensitivity and smooth cycling in progressive presses, bench tools, and handheld priming tools.
• Secure Packaging: Supplied as 1,000 primers per carton, divided into 10 plastic gratings of 100 primers each, weighing approximately 0.47 kg (1.03 lbs) per 1,000-pack.

Product Specifications

• Manufacturer Part Number (MPN): V360247
• Primer Type: Boxer, Small Pistol Magnum (SPM)
• Nominal Primer Diameter: 4.4 mm (~0.175 in)
• Pack Quantity: 1,000 primers (10 sleeves of 100 primers)
• Pack Weight: Approximately 0.47 kg (~1.03 lbs)
• Factory Calibre Compatibility: .357 Magnum, .22 Hornet, .222 Remington, and 5.6×50 R Magnum
• Corrosive Properties: Non-corrosive, non-mercuric

Who is the Sellier & Bellot 4.4 SPM Small Pistol Magnum Primer Pack for?

• Handloaders reloading .357 Magnum ammunition — Requires a 4.4 mm diameter small pistol magnum primer engineered with high brisance and a reinforced cup to withstand high chamber pressures and cleanly ignite slow-burning ball powders.
• Handloaders reloading small-capacity centerfire rifle cartridges — Relies on a 4.4 mm small pistol magnum primer specified by factory load data for calibres such as .22 Hornet and .222 Remington that require consistent ignition in compact internal powder spaces.

Less suitable for: Standard low-pressure pistol calibres featuring 4.4 mm pockets (such as 9mm Luger, .38 Special, .40 S&W, and 7.65 Browning), where the elevated brisance of a magnum primer risks pressure spikes; standard-pressure small pistol Boxer primers should be used instead.