The Sig P226 .357 SIG is the same pistol the Navy SEALs adopted as the Mk25 in 9mm, with a different barrel chambering. Full-size alloy frame, stainless steel slide, DA/SA trigger with a decocker, and a 12+1 magazine. The .357 SIG conversion is straightforward, since the cartridge was developed by Sig and Federal in 1994 specifically for this platform, and the P226 was its launch pistol. At 34 oz unloaded, this is the heaviest gun in the .357 SIG category, and the weight is the point: alloy frames absorb the cartridge's sharp impulse far better than polymer striker pistols at the same barrel length.

The action is the other defining feature. The first trigger pull is a 10-12 lb double-action stroke from a hammer-down position, then every subsequent shot fires single-action at the listed 4.4 lb pull. The decocker safely returns the hammer to the down position without firing. This is the same manual of arms used by federal agencies that issued the P226 for decades, and the same reason many shooters who grew up on Berettas and Sigs prefer the DA/SA system to striker triggers. The Glock G31 Gen4 .357 SIG in the same caliber runs 7.9 oz lighter at 26.1 oz with a striker trigger and 15+1 capacity. Softer recoil management from the alloy weight is the P226's main practical advantage in trade for 3 rounds of capacity.

The P226's history in .357 SIG matters for buyers today. This was a federal duty gun for the U.S. Secret Service and Texas DPS during the late 1990s and 2000s, and it earned the cartridge whatever institutional credibility it has. Production continues in West Hartford, Connecticut. The Sig P226 in 9mm is the more common choice for modern buyers in this frame, but for a shooter who wants the original .357 SIG platform with its decades of duty service behind it, the P226 .357 SIG is the gun that started the cartridge.