What Is 357 Sig Brass?

357 Sig brass is a .40 caliber Smith & Wesson casing that’s factory-modified to fit a .355 inch diameter bullet. It was created to replicate the performance of the classic 357 Magnum cartridge in an auto pistol format. Here at Powder Valley, we are proud to include 357 Sig brass in our extensive inventory of reloading supplies.

Basic Facts About 357 Sig Brass

Here are some critical stats about 357 Sig brass:

  • Date of release: 1994
  • Bullet diameter: .355 inches
  • Neck diameter: .381 inches
  • Case length: .865 inches
  • Base diameter: .424 inches
  • Primary use: as self-defense ammunition for semiautomatic pistols

357 Sig Brass vs. 357 Magnum

So how does 357 Sig brass stack up when compared to the classic 357 Magnum? Here’s a look at the performance stats:

  • Velocity – most 357 Magnum ammo ranges in velocity from about 1200 feet per second to 1500 feet per second. 357 Sig brass, on the other hand, can easily achieve velocities in excess of 1600 feet per second.
  • Muzzle energy – both types of ammo achieve similar results in this category. While 357 Magnum is a bit slower, it often carries a larger projectile.
  • Recoil – the .357 Maximum is famous for its mule-like kick. 357 Sig brass is a bit more gentle in this regard.
  • Trajectory – this is another category in which performance between the two rounds is generally equivalent.

Cartridge Options When Shooting 357 Sig Brass

Unlike some other ammunition such as 38 Special or 44 Magnum, your choice of cartridge is somewhat limited when it comes to 357 Sig brass. However, there are some excellent options on today’s market, including:

  • The Winchester 125 grain PDX –1 Defender – this cartridge uses a bonded bullet, which means that the soft interior is joined, or “bonded,” to the harder exterior. This creates greater momentum when striking the target, hence greater stopping power.
  • The Federal 125-Grain HST – this cartridge has a classic hollow point configuration designed to pass through multiple layers of clothing and other barriers. It offers excellent expansion and target penetration.
  • Sig Sawyer 125- Grain V-Crown – with a grooved design, this cartridge provides excellent all-around performance with its reliable weight retention, penetration, and expansion upon impact.

Can You Modify 40 Caliber Brass to Fit 357 Sig Brass Specifications?

This is a question we often hear from reloaders. The answer is that, while conversion is technically possible, it’s rarely safe. Necking down .40 caliber brass to accommodate a .355 inch bullet places excessive stress on the casing, which can cause the round to fail during firing. This is one modification that’s best left to the ammunition manufacturers. Please don’t try it at home.

Ready to Start Reloading 357 Sig Brass? We Have What You Need

Here at Powder Valley, we carry a huge selection of high-quality reloading supplies, including Hornady 357 Sig brass. Our prices are fair and our customer service is unsurpassed.

Browse our site and get fast delivery on your order. Remember, we can help you shoot more and pay less.