The Radical Firearms RF-15 is a stripped, multi-caliber AR-15-pattern lower receiver intended as the foundation for a custom AR-style build. It is forged from 7075-T6 aluminum and finished with a Type III Class 2 hardcoat black anodized coating. The receiver ships without internals, so buyers add their own lower parts kit, trigger group, and stock to complete the rifle, and it is compatible with .223 Remington/5.56 NATO along with other common AR-15 chamberings. 
 

Key Specifications 

• Brand: Radical Firearms 
• Model: RF-15 
• Material: 7075-T6 Aluminum 
• Finish: Black Hardcoat Anodized (Type III Class 2) 
• Caliber Compatibility: .223 Remington/5.56 NATO 
• Configuration: Stripped Lower Receiver, Multi-Caliber 
   

Detailed Features 

• Forged 7075-T6 aluminum construction for strength over cast alternatives 
• Type III Class 2 hardcoat anodizing resists wear and corrosion 
• Multi-caliber design accepts a range of AR-15-pattern upper receivers 
• Stripped configuration lets builders choose their own trigger, safety, and buffer components 
• Black finish matches standard AR-15 furniture and coatings

Owners building on Radical Firearms lower receivers generally find the machining clean and the anodizing durable, with parts kits from major AR-15 makers dropping in without excessive fitting. The RF-15 is often chosen by first-time builders because it is forged rather than cast, which builders associate with longer-term durability.

Some shooters mention needing to lightly deburr the mag well or pin holes before final assembly, and opinions are split on whether that extra step is a fair trade-off for a forged receiver. Aftermarket support is strong since the RF-15 uses standard AR-15 dimensions, so grips, stocks, and trigger groups from other brands fit without modification. Overall sentiment favors it as a solid, no-frills base for a personalized rifle rather than a showpiece component.