The SIG Sauer SIG516G2 Pro SBR is a 5.56 NATO short-barreled rifle with an 11.5-inch barrel, designated by SIG as a First Responder model (brand part no. WR516G2-556N-11B-PRO-SBR). It pairs a piston-driven action with folding sights and a telescoping stock. An 11.5-inch barrel is a common patrol-carbine length, short enough for vehicles and doorways while keeping useful 5.56 performance. An aluminum handguard surrounds the barrel, and the rifle feeds from a 30-round magazine. The short barrel keeps the rifle easy to handle in tight spaces.

Key Specifications

• Chambering is 5.56 NATO, the standard patrol rifle cartridge.
• Barrel length is 11.5 inches, a compact length that keeps the rifle maneuverable in vehicles and buildings.
• The action is piston-driven, which keeps combustion gas out of the receiver.
• The stock is telescoping, so length of pull adjusts to the shooter and gear.
• The handguard is aluminum, a rigid surround for the short barrel.

Frequently Asked Questions

Do I need ATF approval to buy this? No. As of October 9, 2026, ATF no longer requires Form 4 approval, registration or a tax stamp for short-barreled rifles. It transfers on a Form 4473 with a background check through a Class 3 (SOT) dealer. State and local laws still apply. Taking an SBR across state lines still requires an approved ATF Form 5320.20.

Does the SIG516G2 Pro SBR come with sights? Yes. It comes with folding sights.

How long is the barrel? The barrel is 11.5 inches long, chambered in 5.56 NATO.

Buy the SIG Sauer SIG516G2 Pro SBR, 5.56 NATO, 11.5-Inch, First Responder

As of October 9, 2026, this short-barreled rifle transfers on a Form 4473 with a background check at your Class 3 (SOT) dealer, with no Form 4 or tax stamp; state and local laws still apply. Order through SIG Sauer‘s short-barreled rifles lineup and our Lubbock, Texas team will handle the transfer, and it ships fast to your Class 3 dealer.