Kel-Tec RDB-17 5.56 NATO Bullpup Rifle, 17.3 in Nitrided Threaded Barrel, Adjustable Gas, M-LOK Handguard
The Kel-Tec RDB-17 stands out as a compact, downward-ejecting bullpup with fully ambidextrous controls and an adjustable gas system. Its 17.3-inch 4140 steel barrel is nitrided and threaded 1/2-28, paired with a free-float aluminum M-LOK handguard and a Picatinny rail atop the receiver. The front sight is mounted on a short, separate rail segment positioned forward of the receiver. This example includes flip-up sights, a vertical foregrip, a web sling, and a 30-round Magpul PMAG GEN M3 windowed magazine.
Condition
Overall Condition: Good condition, showing some signs of prior use and handling.
Bore Overall Condition: Excellent - Clean, mirror finish, no signs of wear.
Bore Rifling: Excellent Rifling - Sharp lands and grooves.
Specific Condition Notes: There are minor scratches and blemishes visible on the exterior surfaces.
What’s Included
- Flip-up polymer iron sights, front and rear (installed)
- Polymer vertical foregrip mounted via M-LOK (installed)
- Web sling
- One 30-round Magpul PMAG GEN M3 windowed polymer magazine
The RDB-17 uses a semi-automatic, short-stroke gas piston system with an adjustable regulator ring at the gas block, just behind the muzzle and visible within the forward portion of the handguard through the top cutout. Its downward ejection and fully ambidextrous controls make it adaptable, with an AR-style ambidextrous safety lever and a folding charging handle for streamlined handling.
The 17.3-inch barrel is made from 4140 steel, finished in a durable nitride treatment, and cut with a 1:7 twist and 6-groove, right-hand rifling. The muzzle is threaded 1/2-28 UNEF and fitted with an A2-type flash hider secured with a crush washer.
A free-float aluminum M-LOK handguard provides versatile accessory mounting, while a Picatinny rail atop the receiver supports optics. A short, separate rail segment forward of the receiver carries the front sight. Flip-up polymer sights are installed, and a polymer vertical foregrip is mounted via M-LOK.
The stamped steel upper receiver and polymer stock/furniture keep weight low at about 6.9–7.0 lb, with an overall length of approximately 27.3 inches and a 14.0-inch length of pull. The stock includes a buttpad, sling loop, and sling points. A "P" proof/inspection stamp is present near the chamber.
The rifle is chambered in 5.56mm NATO with a capacity of 30+1 and accepts AR-15/STANAG magazines. One 30-round Magpul PMAG GEN M3 windowed magazine is included.