ProMag SIGA16 StandardBlued Steel Extended 15rd 40 S&W, 357 Sig for Sig P229

The ProMag SIGA16 is a blued steel extended magazine purpose-built for the Sig P229 pistol in .40 S&W and .357 Sig. If you run a P229 and want more rounds on tap without swapping mags mid-session, this 15-round option gives you a meaningful capacity bump while keeping the gun controllable. The extended footprint means it'll print a bit beyond the grip, but that's the trade-off for the extra firepower—and it makes the gun easier to handle during reloads.

ProMag has been making OEM-compatible magazines for decades. This one follows their standard formula: reliable feeding, straightforward construction, and a reasonable price that won't hurt your wallet if you're building out a rotation of carry spares or range mags. The blued steel construction matches the aesthetics of a classic P229, and it's designed to feed both .40 S&W and .357 Sig without modification.

Whether you're a P229 enthusiast looking to extend your capacity at the range, or you want a backup mag that holds more rounds than factory, the SIGA16 is a solid, no-frills choice that does what it promises.

Key Features

• 15-round capacity—five more rounds than standard P229 mags
• Extended design for easier reloading and improved grip purchase
• Blued steel finish matches most P229 platforms
• Reliably feeds both .40 S&W and .357 Sig ammunition
• Direct fit for Sig P229 pistols—no gunsmithing needed

Specifications

Frequently Asked Questions

Will this magazine work in my Sig P229?

Yes. The SIGA16 is designed to fit the Sig P229 directly. It will reliably feed both .40 S&W and .357 Sig cartridges in that platform.

How many rounds does it hold compared to standard P229 magazines?

The SIGA16 holds 15 rounds. Standard P229 magazines typically hold 10 rounds, giving you a five-round increase in capacity.

Does the extended magazine stick out noticeably from the grip?

Yes. The extended design means the basepad extends beyond the bottom of the grip. This is intentional—the extra length provides the additional capacity and can make reloading easier, though it does make the magazine more visible when installed.

Can I use this magazine in both .40 S&W and .357 Sig?

Yes. The SIGA16 is rated for both .40 S&W and .357 Sig without any changes or modification to the magazine.