Hornady Critical Duty .357 Sig 135 Grain FlexLock Ammunition - 20 Rounds

Hornady Critical Duty .357 Sig 135 Grain FlexLock ammunition is purpose-built for defensive carry and duty use. The 135-grain FlexLock projectile combines a polymer tip with Hornady's proven copper jacket technology, designed to deliver consistent performance through a variety of barriers—car glass, sheet metal, heavy clothing—without the feeding and expansion failures that plagued earlier hollow-point designs. If you're running .357 Sig in a duty weapon, patrol carbine, or serious carry pistol, this round gives you the terminal reliability that matters when lives depend on it.

The FlexLock tip is the engineering centerpiece. That polymer insert reliably initiates expansion across a broad velocity window while resisting the clogging that can prevent other hollow-points from opening after penetrating intermediate barriers. In urban and mixed environments where overpenetration or barrier deflection is a real concern, that matters. Critical Duty ammunition has earned credibility with law enforcement agencies and security professionals precisely because it performs the way the box promises.

You get 20 rounds per box. If you carry .357 Sig or outfit a duty gun chambered in this caliber, Critical Duty should be your go-to load for both training and carry. The round balances barrier performance with controlled expansion—no voodoo, just ballistics engineering grounded in what actually happens downrange and in the real world.

Key Features

• FlexLock polymer tip reduces clogging and delivers reliable expansion through barriers
• Copper jacketed projectile for controlled expansion and consistent performance
• Designed for duty and defensive carry applications
• Proven barrier performance in automotive glass, sheet metal, and intermediate barriers
• Loaded to pressure and velocity specifications optimized for .357 Sig handguns

Specifications

Frequently Asked Questions

What makes the FlexLock design different from standard hollow-points?

The FlexLock bullet uses a polymer tip that resists clogging when passing through barriers like auto glass, heavy fabric, or steel. This means the projectile is more likely to expand reliably after barrier penetration, rather than failing to open as older hollow-point designs sometimes did.

Is Hornady Critical Duty rated for duty and defensive carry?

Yes. Hornady Critical Duty ammunition is designed specifically for law enforcement and security use. The load balances barrier performance with expansion consistency, making it suitable for defensive carry and duty applications.

What caliber is this ammunition?

.357 Sig. Verify that your handgun is chambered in .357 Sig before purchasing. This caliber is distinct from .357 Magnum and requires a .357 Sig-specific firearm.

How many rounds are in a box?

Each box contains 20 rounds of Hornady Critical Duty .357 Sig ammunition.