The KelTec R50 Defender 5.7x28mm SBR is a short-barreled sport utility rifle with a 9.6-inch barrel and a stock. KelTec describes it as the firepower of the P50 combined with the side-folding versatility of the R50, and pitches it as a trail gun, camping companion and home defender. It carries 50 rounds of 5.7x28mm and weighs 4.3 pounds unloaded. Plenty of rail space for a light and optic, plus a stock that folds the rifle down to 16.4 inches, keeps it easy to carry and stow.

Key Specifications

• Chambering is 5.7x28mm, the small, fast cartridge the whole R50 family is built around.
• Magazine capacity is 50 rounds, a deep supply on board for range days and home defense.
• The barrel is 9.6 inches, which is what makes this a short-barreled rifle and keeps it compact.
• Overall length is 25.2 inches, or 16.4 inches with the stock folded for storage and transport.
• Unloaded weight is 4.3 pounds, light enough for a long carry.

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.

How short does it fold? KelTec lists a folded length of 16.4 inches against 25.2 inches overall.

What are the twist rate and trigger pull? KelTec lists a 1:7-inch twist and a 5-pound trigger pull for the R50 Defender.

Buy the KelTec R50 Defender 5.7x28mm SBR, 9.6-Inch Barrel

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 KelTec‘s short-barreled rifles lineup and our Lubbock, Texas team will handle the transfer, and it ships fast to your Class 3 dealer.