.357 SIG Ammo
.357 SIG ammo for SIG P226, P229, Glock 31/32, and police trade-ins. The bottlenecked pistol cartridge that briefly captured law enforcement interest — what it actually does, how it compares to 9mm and .40 S&W, and why agencies moved back.
Price History
Best Prices Now
$/rd = listed price + estimated shipping. Sorted by true cost.
| Product | $/rd | |
|---|---|---|
| 357 Sig – CorBon Range Day 125 Grain Full Metal Jacket – 1000 Rounds Best 125gr · FMJ · brass | $0.48 | Buy → |
| 1000 Round Case – 357 Sig Speer Gold Dot LE GDHP Hollow Point Ammo – 53918 · HP · brass | $0.60 | Buy → |
| 357 Sig – HSM 124 Grain Plated Flat Point – 1000 Rounds 124gr · plated flat point · brass | $0.63 | Buy → |
| 350 Round Can – 357 Sig Speer Gold Dot LE GDHP Hollow Point Ammo – 53918 – Packed in M19A1 Canister · HP · steel | $0.68 | Buy → |
| 1000 Round Case – 357 Sig 125 Grain Federal HST Ammo – P357SHST1 125gr · HST · brass | $0.70 | Buy → |
| 1000 Round Case – 357 SIG 100 Grain Frangible CleanFire Speer Ammo – 53368 100gr · Frangible · brass | $0.80 | Buy → |
| 357 Sig – CorBon Range Day 125 Grain Full Metal Jacket – 50 Rounds 125gr · FMJ · brass | $0.84 | Buy → |
| 50 Round Box – 357 Sig Speer Gold Dot LE GDHP Hollow Point Ammo – 53918 · HP · brass | $0.98 | Buy → |
| Fiocchi - 357 Sig - 124 Grain - FMJ - 50 Rounds 124gr · FMJ | $0.99 | Buy → |
| 357 Sig – HSM 124 Grain Plated Flat Point – 50 Rounds 124gr · FP | $1.00 | Buy → |
| 357 SIG – CorBon 125 Grain DPX Hollow Point – 200 Rounds 125gr · DPX · brass | $1.01 | Buy → |
| 50 Round Box – 357 Sig 125 Grain Federal HST Ammo – P357SHST1 125gr · HST · brass | $1.02 | Buy → |
| 357 SIG – CorBon 125 Grain Jacketed Hollow Point – 200 Rounds 125gr · JHP · brass | $1.02 | Buy → |
| 200 Round Case – 357 Sig 147 Grain XTP Hollow Point Hornady Ammo – 9131 147gr · XTP Hollow Point · brass | $1.20 | Buy → |
| 50 Round Box – 357 SIG 100 Grain Frangible CleanFire Speer Ammo – 53368 100gr · Frangible · brass | $1.20 | Buy → |
| 200 Round Case – 357 Sig 135 Grain FlexLock Hornady Critical Duty Ammo – 91296 135gr · JHP · brass | $1.40 | Buy → |
| 200 Round Case – 357 Sig 125 Grain Jacketed Hollow Point Federal HST Ammo – P357SHST1S 125gr · JHP · brass | $1.50 | Buy → |
| 357 SIG – CorBon 125 Grain Jacketed Hollow Point – 20 Rounds 125gr · JHP · brass | $1.75 | Buy → |
| 357 SIG – CorBon 125 Grain DPX Hollow Point – 20 Rounds 125gr · DPX · brass | $1.75 | Buy → |
| Hornady Critical Duty 357 SIG 135 GR FlexLock 20 RDS (91296) 135gr · JHP · brass | $2.04 | Buy → |
Best .357 SIG by Use Case
Personal Defense
125gr JHP at 1,350-1,450 fps is the .357 SIG defensive standard. The cartridge was specifically engineered to replicate .357 Magnum revolver performance from a semi-automatic. Federal HST 125gr, Speer Gold Dot 125gr, and SIG V-Crown 125gr are the primary defensive loads. Penetration and expansion in gel runs 12-14 inches with expansion to ~0.55-0.65" — comparable to premium 9mm +P. The velocity advantage is real at muzzle; at 25 yards the difference narrows.
- · Federal HST 125gr JHP
- · Speer Gold Dot 125gr JHP
- · SIG V-Crown 125gr JHP
Range & Practice
124-125gr FMJ for range use. Factory FMJ runs $0.65-0.90/round — notably more expensive than 9mm practice ammo. Blazer Brass 125gr FMJ is the most affordable standard factory load. There's no budget steel-case .357 SIG, which adds up over time. Many .357 SIG owners run 9mm barrels for the majority of their practice — P226 and Glock 31/32 both accept factory conversion barrels.
- · Blazer Brass 125gr FMJ
- · Magtech 125gr FMJ
- · Federal American Eagle 125gr FMJ
Common Questions
What is .357 SIG?
.357 SIG was developed in 1994 by SIG Sauer and Federal Cartridge as a joint project. The goal was explicit: replicate the terminal performance of the .357 Magnum 125gr JHP — which had established a strong law enforcement reputation from revolver-era studies — in a cartridge that worked in high-capacity semi-automatic pistols.
The engineering solution is a bottlenecked case: the .40 S&W case necked down to accept a 9mm (.355”) bullet. The bottleneck allows higher operating pressure in a standard pistol-length action without the longer case length that a true magnum cartridge would require. The result: a 125gr bullet at 1,350-1,450 fps from a 4” barrel — significantly faster than standard 9mm (1,150 fps) and approaching the revolver .357 Magnum velocities the designers were targeting.
Law enforcement adoption — and departure
Several agencies adopted .357 SIG in the late 1990s and 2000s:
- Texas Department of Public Safety (the standard bearer — used it for over 20 years)
- US Secret Service
- Various state and local agencies
The rationale was real ballistic performance and the bottleneck design’s reputation for reliable feeding. The liability argument was that the cartridge had documented stopping performance data inherited from .357 Magnum research.
But the trend reversed. Most agencies that adopted .357 SIG have transitioned back to 9mm since approximately 2015. The reasons:
- Modern 9mm hollow point ammunition (HST, Gold Dot, Critical Duty) closed the terminal performance gap significantly. The FBI’s 2014 justification for returning to 9mm explicitly cited improved modern 9mm loads.
- .357 SIG ammunition costs roughly 40-60% more than 9mm, which affects training volume.
- Increased recoil reduces split times and follow-up shot accuracy under stress.
- Barrel wear is accelerated at .357 SIG’s high velocity.
Texas DPS transitioned from .357 SIG to 9mm in 2017 — the symbolic end of law enforcement enthusiasm.
Ballistics comparison
| .357 SIG 125gr | 9mm +P 124gr | .40 S&W 165gr | |
|---|---|---|---|
| Velocity (4” barrel) | ~1,400 fps | ~1,220 fps | ~1,130 fps |
| Energy | ~544 ft-lbs | ~410 ft-lbs | ~468 ft-lbs |
| Recoil (28oz gun) | ~11 ft-lbs | ~7 ft-lbs | ~10 ft-lbs |
| Factory ammo cost | High | Low | Moderate |
The velocity advantage is real and measurable. The terminal performance advantage over modern 9mm +P at typical defensive distances (under 25 yards) is marginal in gel testing. The recoil and cost disadvantage is concrete.
The conversion barrel option
Both SIG P226/P229 and Glock 31/32 (the primary .357 SIG platforms) accept factory drop-in 9mm conversion barrels. This is practical: buy the pistol in .357 SIG (often available at good prices as police trade-ins), run a conversion barrel for 90% of practice, use the .357 SIG barrel for carry. Same magazines work for both.
Lone Wolf (for Glock) and SIG factory barrels are the standard conversion options.
Who still shoots .357 SIG
People who bought P226 or P229 trade-ins (often priced attractively as LE surplus) and appreciate the performance. The cartridge performs as advertised — there’s nothing wrong with it, the market simply moved.
Recoil enthusiasts who find .357 SIG more satisfying than standard 9mm. The fireball and snap are real; some shooters prefer it.
Handloaders can extract excellent performance from the case — maximum-pressure loads push the 125gr Gold Dot past 1,500 fps from a 4” barrel.
Where it doesn’t make sense: as a primary defensive choice when 9mm is available. Modern 9mm +P loads match .357 SIG terminal performance in gel testing, at lower cost, lower recoil, and with deeper factory ammo selection.
Brand guide
Federal HST 125gr JHP — the defensive standard; excellent gel performance. ~$0.85–1.15/rd.
Speer Gold Dot 125gr JHP — LE service load; bonded construction. ~$0.85–1.10/rd.
SIG V-Crown 125gr JHP — manufacturer’s premium load; designed for the cartridge. ~$0.90–1.20/rd.
Blazer Brass 125gr FMJ — most affordable FMJ; range standard. ~$0.65–0.85/rd.
Magtech 125gr FMJ — Brazilian manufacture; consistent quality. ~$0.60–0.82/rd.
Federal American Eagle 125gr FMJ — reliable practice load. ~$0.65–0.88/rd.
Price guide (2025–2026)
| Category | Good deal | Fair | Overpaying |
|---|---|---|---|
| FMJ practice | $0.55–0.78/rd | $0.78–1.00/rd | $1.25+/rd |
| Defensive JHP | $0.75–1.00/rd | $1.00–1.35/rd | $1.60+/rd |
Firearms chambered in .357 SIG
- SIG P226 — the primary platform; full-size; 15+1 capacity; police trade-ins widely available
- SIG P229 — compact variant; 13+1; more concealable; also available as police trade-ins
- Glock 31 — full-size; 15+1; the Glock platform answer to P226
- Glock 32 — compact; 13+1; most common .357 SIG Glock
- Glock 33 — subcompact; 9+1; smallest .357 SIG Glock
- FN Five-SeveN — not chambered, but sometimes confused due to similar bottleneck design (it’s 5.7x28mm, entirely different)
What could be better?
- Best price
- $0.48/rd
- Avg tracked
- $1.32/rd
- Products tracked
- 25
- Retailers stocking
- 4
Best deals and market moves. Every Friday.