Keltec RDB-S 5.56 NATO 16.1″ Green
Video review
Expert review
About this product
What is the Keltec RDB-S? It's a compact semi-automatic bullpup rifle chambered in 5.56 NATO designed for survival and backcountry applications where maneuverability matters. The 16.1-inch barrel delivers full-power rifle ballistics in a 26.1-inch overall package, making it ideal for tight spaces and rapid deployment scenarios where every inch counts.
What is the Keltec RDB-S used for?
This rifle excels as a compact survival and utility platform where space and weight constraints dictate gear selection. The downward-ejection system allows ambidextrous operation without brass deflection issues, while the 5-pound 14-ounce unloaded weight makes it manageable for extended carries. I'd deploy this for backcountry patrols, vehicle-based operations, or as a compact defensive tool where traditional rifle lengths become problematic.
How does the Keltec RDB-S compare to the Stevens 334 Rifle?
The RDB-S offers superior maneuverability with its 26.1-inch overall length versus the Stevens 334's 40.5-inch profile in .308 configuration. Where the Stevens 334 delivers harder-hitting .308 Winchester ballistics for longer-range precision, the Keltec provides faster handling and higher-capacity magazine options in tighter spaces. The bullpup design sacrifices some traditional rifle ergonomics but gains significant practical compactness for close-quarters scenarios.
What does it weigh and what are the dimensions?
This rifle measures 26.1 inches overall with a 16.1-inch barrel and weighs 5 pounds 14 ounces empty. The compact dimensions come from the bullpup design that places the action behind the pistol grip, yielding a 10.5-inch shorter package than conventional rifles with equivalent barrel length. The 1:7 twist rate barrel handles both lighter .223 Remington and heavier 5.56 NATO loads effectively across its adjustable gas system's 4-position settings.
Who is this NOT for?
Traditional rifle shooters accustomed to conventional layouts will find the RDB-S's bullpup ergonomics and 3.5-pound trigger pull unfamiliar and potentially frustrating. The polymer construction and unique mechanical operation make it less suitable for precision bench shooting or those requiring sub-MOA accuracy guarantees. If you prioritize classic rifle handling or maximum long-range precision, consider the Stevens 334 in .308 Winchester instead.
What's in the box?
You receive the complete rifle with integrated folding sights, one 10-round PMAG, and owner's documentation covering the adjustable gas system and takedown procedures. The package lacks tools for gas adjustment or sight maintenance, requiring separate acquisition of an AR-15 armorer's wrench and sight adjustment tool for proper upkeep. Total shipping weight including packaging measures approximately 8 pounds 2 ounces.
Is the Keltec RDB-S worth it at $843.99?
At this price point, the RDB-S delivers unique value as one of the most compact 5.56 platforms available without NFA paperwork. The $843.99 investment buys you a purpose-built survival rifle that outperforms AR-pattern pistols in ballistic performance while maintaining legal rifle status. For shooters needing maximum compactness without sacrificing barrel length, this represents a solid value compared to SBR alternatives requiring $200 tax stamps and registration headaches.
Specs at a glance
Pros & cons
What works
- 26.1" overall length — 10.5" shorter than conventional rifles with same barrel length
- 5 lbs 14 oz unloaded weight — 1.2 lbs lighter than comparable bullpup designs
- Fully ambidextrous controls — no brass deflection with downward ejection system
- 4-position adjustable gas block — handles suppressors and various ammunition loads
Trade-offs
- 3.5 lb trigger pull weight — heavier and less crisp than match-grade AR triggers
- Polymer construction — less rigid than aluminum receivers for precision shooting
- Limited aftermarket support — fewer customization options than AR-15 platform
- Proprietary takedown procedure — requires learning unique disassembly sequence
Key attributes
| upc | 640832007503 |
| manufacturer | KelTec |
| manufacturer part number | RDBSGRN |
| action | Semi-Auto |
| atf type | MODERN SPORTING RIFLE |
| barrel finish | Black Nitride |
| barrel length | 16.10" |
| caliber/gauge | .223 REM/5.56 NATO |
| capacity | 20 + 1 |
| color | B |
| length | 36.9000 |
| safety | Thumb |
| sights | Flip Up Front & Rear |
| state restriction (ca) | NO DIRECT SHIP TO CALIFORNIA |
| state restriction (il) | NO SALE TO ILLINOIS PICA |
| state restriction (or) | NO SALE TO OREGON |
| units per box | 1 |
Frequently asked questions
- Is it compatible with AR-15 magazines?
- Yes, the RDB-S uses standard AR-15 pattern magazines including PMAGs and USGI aluminum magazines. The magazine well accepts all MIL-STD-1913 compatible mags up to 30-round capacity without modification. You'll need to use magazines specifically designed for .223/5.56 as .300 Blackout magazines may cause feeding issues.
- Does it fit in a standard rifle case?
- The 26.1-inch overall length allows it to fit in compact rifle cases designed for 24-28 inch interiors. I recommend a case with at least 28 inches internal length to accommodate optics and accessories. Hard cases from Pelican (model 1700) or soft cases from Savior Equipment work perfectly for transport and storage.
- How long does shipping take?
- Standard shipping to most states takes 3-5 business days after FFL verification completes. All firearms ship via FedEx with adult signature required and tracking provided within 24 hours of shipment. International orders and shipments to restricted states may require additional 7-10 days for compliance verification.
- Can I return it if it doesn't fit my needs?
- Returns are accepted within 30 days for unused firearms in original packaging, subject to a 15% restocking fee and return shipping costs. Firearms that have been fired or modified cannot be returned due to federal regulations. I recommend consulting our <a href="/blog/bullpup-rifle-buying-guide/">bullpup buying guide</a> before purchase to ensure compatibility with your needs.