The ProMag 20-round steel magazine for Sig Sauer P226 in .357 Sig or .40 S&W is a capacity upgrade built for shooters who want more rounds downrange without swapping mags. Whether you're at the range running drills, competing, or training for defensive carry, this extended magazine doubles your on-board ammo compared to factory P226 magazines. The blue-finished steel construction delivers the durability you'd expect from a workhorse EDC or duty pistol, and the straightforward design integrates seamlessly with your P226 platform.

ProMag engineered this magazine with heat-treated steel for strength and a chrome-silicon wire spring that's also heat-treated for consistent feeding and long service life. The polymer base-plate and follower lock-plate (molded from DuPont Zytel) are designed to take the punishment of field use and reloading without cracking or wearing prematurely. The combination of steel body and engineered polymers balances weight, corrosion resistance, and reliability—important when you're relying on your gear.

Fit and function matter in a magazine, and this one is tailored specifically for the P226 in these two calibers. Before installing, verify your pistol's cartridge to ensure compatibility. The 20-round capacity makes it ideal for sport shooting, training sessions, and situations where mag capacity gives you a real tactical advantage.

Key Features

• 20-round extended capacity for Sig Sauer P226 (.357 Sig / .40 S&W)
• Heat-treated blued steel body for corrosion resistance and durability
• Chrome-silicon wire spring, heat-treated for reliable feeding
• DuPont Zytel polymer base-plate and follower lock-plate for impact resistance
• Drop-free design compatible with P226 platform

Specifications

Frequently Asked Questions

Will this magazine work with my Sig P226?

Yes—this magazine is designed specifically for the Sig Sauer P226 platform in .357 Sig or .40 S&W. Verify your pistol's cartridge before purchasing to ensure a proper match.

What calibers does this magazine support?

This ProMag magazine is chambered for .357 Sig and .40 S&W. It will not function safely in other calibers.

Is the blue steel finish corrosion-resistant?

The blued steel provides good corrosion resistance for typical storage and field conditions, though it will require the same basic maintenance care as any blued-steel firearm magazine. Store in a dry environment and clean/dry after wet conditions.

What's the base-plate made of, and is it durable?

The base-plate and follower are molded from DuPont Zytel, a proprietary polymer engineered to withstand repeated loading, unloading, and field handling without cracking or wearing prematurely.