Last reviewed: 2026-04-18 by Jake Terry, FFL07/SOT3, NRA-certified firearms instructor.
The 357 Sig 115 grain JHP from Underwood pairs a high-velocity bottleneck cartridge with Nosler’s Assured Stopping Power (ASP) projectile design, engineered for shooters who carry compact semi-automatics chambered in 357 Sig and prioritize barrier-blind expansion in self-defense scenarios. At 1550 feet per second and 614 foot-pounds of muzzle energy, this load places energy on target faster than 9mm +P while maintaining controllable recoil in mid-frame pistols. The 357 Sig cartridge is a bottlenecked semi-automatic round designed in 1994 to replicate the terminal ballistics of the 125-grain .357 Magnum revolver load in a platform that fits double-stack magazine wells.
Performance at a Glance
Underwood loads this round with nickel-plated brass cases, which resist tarnish on contact with leather holsters and moisture better than raw brass. The Boxer primer allows you to reload the case after firing. Flash-suppressed powder keeps muzzle flash low in low-light encounters, preserving your ability to track the threat and your sights. The Nosler JHP uses precision-cut skives in the jacket mouth to initiate expansion without requiring high velocity through drywall or auto glass — a design feature you see in other barrier-blind projectiles but executed here with a sectional density of 0.130 and a ballistic coefficient (G1) of 0.109, which keeps the bullet stable through intermediate barriers without fragmenting prematurely.
| Spec | Value |
|---|---|
| Caliber | 357 Sig |
| Bullet weight | 115 grains |
| Bullet type | Jacketed Hollow Point |
| Bullet brand/model | Nosler Jacketed Hollow Point |
| Muzzle velocity | 1550 feet per second |
| Muzzle energy | 614 foot-pounds |
| Rounds/box | 20 |
| Case | Nickel Plated Brass |
| Primer | Boxer |
| Corrosive | No |
| Reloadable | Yes |
| Intended use | Self Defense |
| Manufacturer | Underwood Ammo |
| Country of origin | United States of America |
Underwood field-tests all loads with the firearms their customers carry — SIG P229, Glock 31, Springfield XD, and similar platforms. Shop our full selection of 357 Sig ammo to compare grain weights and bullet designs for training, competition, or duty carry.
Safe Handling & Compliance
Federal law requires purchasers to be at least 18 years old for rifle and shotgun ammunition, and at least 21 for handgun ammunition. Ammunition cannot be shipped to certain states, counties, and cities — review our ammunition shipping restrictions before ordering. Store ammunition in a cool, dry location away from heat sources and out of reach of unauthorized users.
- Treat every firearm as if it is loaded. Keep your finger off the trigger until sights are on target and you have made the decision to fire. Be sure of your target and what lies beyond it. Never point a firearm at anything you do not intend to shoot. Review the NRA’s four universal rules of firearms safety.
- This ammunition contains lead. California Proposition 65 requires manufacturers to warn that lead exposure can cause cancer, birth defects, and reproductive harm. Wash hands after handling ammunition or spent casings.
- Verify that your firearm is chambered for 357 Sig before loading. Do not use 357 Sig ammunition in firearms chambered for 9mm, .40 S&W, or any other cartridge. Consult your firearm’s manual for maximum chamber pressure (SAAMI spec for 357 Sig is 40,000 psi).
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