The Kel-Tec RDB (Rifle, Downward-ejecting, Bullpup) is an American semi-automatic rifle.
The RDB was created in 2014, and is of a similar design to the larger RFB. The weapon is advertised as "The Bullpup Done Right", with its downward ejection system being touted as removing the side ejection disadvantage of normal bullpups. The weapon is claimed to also be "an excellent suppressor host".
The RDB looks very similar to the RFB, but instead of ejecting forward, the weapon ejects downwards behind the magazine. The RDB is chambered in 5.56×45mm NATO instead of 7.62×51mm NATO that is chambered in its larger brother. The rifle has an adjustable gas system for recoil control, and its barrel has a 1/7" twist. The rifle can chamber both .223 Remington and 5.56 NATO.
Variant of the RDB with wooden furniture shown off at SHOT Show 2014. It appears that the M43 never advanced beyond prototype stages and is assumed to have been canceled.
Sporting variant of the RDB with a SU-series-style stock. Has a 20.5 in (52 cm) barrel.
Sporting variant of the RDB with a slightly different style of stock. Has a 16.1 in (41 cm) barrel.