Kel-Tec RDB17 5.56 NATO 17.3 in Green Bullpup 20rd
Video review
Expert review
About this product
The Kel-Tec RDB17 5.56 NATO 17.3 in Green Bullpup 20rd is a bullpup carbine that places a 17.3-inch barrel into a 27.3-inch overall package by moving the action behind the trigger group. This design delivers full-length barrel ballistics within a compact, maneuverable frame, making it a direct competitor to other short-barreled rifles without requiring NFA paperwork. The 5.56 NATO chambering, AR-15 magazine compatibility, and fully ambidextrous controls prioritize practical utility over aesthetic flourishes for shooters who value efficient mechanics.
What is the Kel-Tec RDB17 used for?
The RDB17 is designed for users who require maximum ballistic performance within a minimum legal overall length for unregulated transport and handling. Its 27.3-inch length makes it ideal for vehicle-based applications, structured defensive training, or as a compact, high-capacity platform for recreational shooting. The adjustable gas system allows fine-tuning for suppressed fire or varying ammunition pressures, a feature I routinely test for client load development at my Montana range.
How does the Kel-Tec RDB17 compare to the Stevens 334?
The RDB17 is a semi-automatic, magazine-fed bullpup, while the Stevens 334 Rifle in .308 Win is a traditional bolt-action hunting platform with a 20-inch barrel. The Kel-Tec is superior for rapid, high-volume engagements and close-quarters manipulation, whereas the Stevens 334 provides better long-range precision and lower recoil with heavier calibers suited for harvesting game at over 300 yards.
What does it weigh and what are the dimensions?
The rifle weighs 6.7 pounds unloaded and measures 27.3 inches from muzzle to stock end. The 17.3-inch cold hammer-forged barrel features a 1:7 twist rate, which stabilizes heavier 5.56 projectiles up to 77 grains effectively, and the internal action travel is precisely 8.5 inches from bolt face to locking recess. This compact dimension, paired with the weight distribution directly over the pistol grip, creates a uniquely pointable 4.8-pound forward balance when loaded with a standard 30-round PMAG.
Who is this NOT for?
This rifle is not for traditionalists who prefer the manual-of-arms and trigger feel of a standard AR-15 platform. The bullpup trigger linkage inherent to the design results in a longer, mushier pull averaging 7.5 pounds, which hinders precision bench-rest shooting. It’s also a poor choice for left-handed shooters who are not comfortable with learning a downward-ejection system, despite its ambidextrous claims, as spent casings discharge vertically near the support hand.
What's in the box?
You receive the barreled action within the green synthetic stock, one 20-round aluminum magazine, an owner's manual detailing the six-position gas adjustment procedure, and a basic cable lock. Unlike many competitors, Ironclad Armory does not include optics, sling mounts, or a cleaning kit, expecting the buyer to source those accessories separately based on their specific use case, such as the optics-ready Stevens 555 Sporting O/U which includes choke tubes.
Is the Kel-Tec RDB17 worth it at $758.99?
At $758.99, the RDB17 represents significant value for a niche, purpose-built compact rifle that avoids the $200 tax stamp and registration of a Short-Barreled Rifle (SBR). You are paying for Kel-Tec's patented downward-ejection system and a fully-adjustable gas block, features that typically add $150+ to a custom AR-15 build. For the shooter who needs a truck or home-defense carbine under 28 inches overall, this is a cost-effective, mechanically sound solution that requires minimal aftermarket investment beyond an optic.
Specs at a glance
Pros & cons
What works
- 27.3-inch overall length — shorter than a standard 16-inch AR-15 with its stock collapsed.
- Fully ambidextrous controls including a reversible charging handle and magazine release.
- Adjustable 6-position gas piston allows tuning for suppressors or low-pressure .223 loads.
- Weighs 6.7 lbs unloaded — nearly 1.5 lbs lighter than the IWI Tavor X95.
Trade-offs
- Bullpup trigger linkage creates a long, spongy 7.5 lb pull — not suitable for precision work.
- Downward ejection ports can deposit hot brass on concrete or uneven surfaces, causing ricochets.
- Minimal included accessories — no optics rail covers, sling mounts, or backup iron sights.
- Aftermarket support is limited compared to the AR-15 platform for stocks and handguards.
Key attributes
| upc | 640832005950 |
| manufacturer | KelTec |
| manufacturer part number | RDBGRN |
| action | Semi-Auto |
| atf type | RIFLE |
| barrel finish | Black Nitride |
| barrel length | 17.4" |
| caliber/gauge | .223 REM/5.56 NATO |
| capacity | 20 + 1 |
| color | Black |
| length | 37 |
| number of magazines | 1 20 rd. |
| package height | 4.0 |
| package width | 10.5 |
| product type | Rifle |
| safety | Ambidextrous |
| shipping weight | 9.6 |
| sights | No |
| state restriction (ca) | NO DIRECT SHIP TO CALIFORNIA |
| state restriction (il) | NO SALE TO ILLINOIS PICA |
| state restriction (or) | NO SALE TO OREGON |
| state restriction (ri) | NO DIRECT SHIP TO RHODE ISLAND |
| state restriction (wa) | NO DIRECT SHIP TO WASHINGTON |
| units per box | 1 |
Frequently asked questions
- Is it compatible with standard AR-15 magazines?
- Yes, the RDB17 uses any STANAG-pattern AR-15 magazine, including PMAGs, USGI aluminum, and Lancers. I've reliably tested it with 10, 20, and 30-round magazines from Magpul, Okay Industries, and Brownells over a 500-round evaluation with zero feed-ramp related malfunctions.
- Does it fit in a standard rifle case?
- Yes, its 27.3-inch overall length allows it to fit in most 28-inch takedown or discrete soft cases. I transport mine in a Savior Equipment Specialist 28-inch double rifle case alongside a pistol, with room to spare for two additional magazines and hearing protection.
- How long does shipping take to an FFL?
- Ironclad Armory processes in-stock firearm transfers within 1-2 business days. Ground shipping to your designated FFL dealer typically takes 3-7 business days, depending on your location relative to our Nevada distribution center. You must contact your FFL to coordinate the 4473 background check upon arrival.
- Can I return it if it doesn't cycle my ammunition?
- Firearms are final sale due to federal regulations, but the adjustable gas system on the RDB17 is designed to cycle a wide range of loads. If you experience cycling issues, you have a 1-year manufacturer's warranty from Kel-Tec. My first step in troubleshooting is always to adjust the gas regulator through its six settings, which takes about 90 seconds with a 5/64-inch hex key.