Sig Sauer M400

Chambered for rifle calibers and boasting a stabilizing brace, optics, and up to 30-round magazines, the M400 stretches the definition of “pistol.” Also informally known as the Sig Sauer PM400 (the “P” stands for “Pistol”), the M400 is a tactical AR pistol designed for competitive shooters and law enforcement officers. Browse our selection of SIG M400s and find the one that’s right for you.

Sig Sauer M400 Elite 5.56mm Pistol with Sig Brace and KeyMod Rail

  • $1,650.00 $1,399.99
  • Brand: Sig Sauer
  • Item Number: PM400-11B-ELITE

Sig Sauer PM400 Swat 5.56 Centerfire Pistol with SB15 Stabilizing Brace

  • $1,469.99 $1,249.99
  • Brand: Sig Sauer
  • Item Number: PM400-11B-S-PSB

Sig Sauer M400 5.56mm FDE Centerfire Pistol with SB15 Stabilizing Brace

  • $1,519.00 $1,049.00
  • Brand: Sig Sauer
  • Item Number: PM400-11B-EC-FDE-PSB

AR Pistols Designed For Performance

The M400 is Sig Sauer's line of AR pistols built for those who need a customizable gun they can rely on. Chambered for either 5.56 NATO or .300 AAC Blackout cartridges, it combines the portability of a handgun with the firepower of a rifle. They also come with a variety of barrel lengths and different attachments, so you can find the SIG M400 that's right for your use case.

Looking for other tactical and compact options? Check out our other AR-15 pistols for sale. We also have compact handguns designed specifically for concealed carry. If you want something larger, we've curated a large selection of AR-15 rifles, as well as other semi-auto rifles from industry-leading manufacturers.

Explore all of these and more in our massive collection of guns for sale!

High-Quality Firearms, Ammo, and More

Sportsman's Outdoor Superstore has been serving our community of fellow gun owners since 2007. We're proud to offer not only high-quality Sig Sauer M400s, but also a selection of outdoor gear and ammo for sale.

But most importantly, we offer industry-leading service. Every firearm order comes with fast and free shipping nationwide. Plus, if it's from our Used Gun Collection, it comes with a money-back, no-questions-asked returns for up to 30 days.

If you have any questions, reach out to our in-house customer service team. We'll get you the help you need.

Frequently Asked Questions

Is the Sig Sauer M400 a pistol or a rifle?

The M400 is technically a pistol. However, since it's usually manufactured with a pistol brace, chambered for rifle rounds, and has an extended barrel, it looks and feels like a rifle.

Should I get an SIG M400?

If you're a competitive shooter, the M400 is a lightweight alternative to semi-auto rifles without compromising on firepower or accuracy. Since it was designed with military use in mind, it has all the features that law enforcement and security officers need in their work. But most importantly, if you're a shooter who wants a fully customizable firearm to take to the range, the M400 is perfect.

Can you deliver my M400 to my house?

Firearms can be sent through the mail, but they can only be received by someone with an FFL. Since most people do not have this, we'll send your order to your local FFL dealer. You can pick up your firearm from them. Before placing your order, we recommend contacting your dealer and making sure they'll accept the package. If you don't, they might return your package to us. We are not responsible for returned packages.