SA-4 Forged Builder Combo

What's in the Box

• Shield Arms SA-4 Forged Mil-Spec Lower Receiver — 7075-T6 forged aluminum, CNC-machined to mil-spec dimensions, Mil 8625 Type 3 Class 2 hard-coat anodized finish, MULTI caliber marking, threaded bolt catch pin hole, upper tension screw; serialized firearm, FFL transfer required
• Mil-Spec Forged Upper Receiver — 7075-T6 forged aluminum, Picatinny top rail, forward assist tower, ejection port dust cover provisions, mil-spec barrel extension threading; fits all mil-spec barrels and handguards
• Radian Weapons Raptor-LT Charging Handle — Patented ambidextrous design for AR15/M16; operable from either side with one hand; slim, snag-free latch profile; aluminum construction with Type III hard-coat anodized finish
• Radian Weapons Talon Ambidextrous Safety Selector — Billet aluminum; mounts fire control levers on both sides of the lower; positive detent engagement; slim profile compatible with virtually any AR-15 grip; available in 45° and 90° throw
• Mil-Spec End Plate — Standard mil-spec end plate for buffer tube installation; compatible with all mil-spec buffer tubes and QD sling sockets

Radian Weapons Raptor-LT: The Raptor-LT is Radian's lightweight ambidextrous charging handle for the AR-15/M16 platform—featuring the same patented ambi latch mechanism as the full-size Raptor in a slimmer, lighter package. Both latches are fully functional, allowing one-handed charging from either side without repositioning your grip or breaking your cheek weld. The snag-free latch profile clears optics and scope mounts cleanly, and the Type III hard-coat anodized finish matches the matte black of the included upper and lower receivers. For any build, the Raptor-LT represents an immediate, meaningful upgrade over a standard mil-spec charging handle.

Radian Weapons Talon Ambidextrous Safety Selector: The Talon is the benchmark ambi safety selector for the AR-15 platform—machined from billet aluminum and finished to Radian's precision standard. It mounts fire control levers on both sides of the lower receiver, giving left-handed shooters full fire control access and giving right-handed shooters the ability to manipulate the safety with either hand. Positive detent engagement, a slim profile that clears virtually any AR-15 grip, and the durability to handle heavy round counts across years of use. The Talon is standard kit on professional duty builds and serious competition rifles—and it's in this combo from day one.

Technical Specifications

What You Still Need to Complete Your Build

The SA-4 Forged Builder Combo gives you the upper and lower receivers, charging handle, safety selector, and end plate. To complete a functioning rifle, you'll also need:

• Lower Parts Kit (LPK): Trigger group, pistol grip, bolt catch, magazine catch, takedown and pivot pins, and all associated springs and detents
• Buffer Tube, Buffer, and Buffer Spring: Mil-spec or commercial spec depending on your stock choice
• Stock or Pistol Brace
• Barrel, Barrel Nut, and Gas System
• Handguard
• Bolt Carrier Group (BCG)
• Muzzle Device

If you'd prefer a complete assembled lower ready to accept an upper, see the SA-4 Complete Lower lineup—available in Mil-Standard, Enhanced, and Premium configurations.

Frequently Asked Questions

Who Should Buy the SA-4 Forged Builder Combo

• First-Time AR-15 Builders: Shooters starting their first build who want to save money on the core receiver components without sacrificing quality—and who want the Radian Raptor-LT and Talon already sourced and in hand when the build begins
• Experienced Builders Starting a New Project: Builders who know exactly what they want in an upper and lower and want to lock in savings on the receiver set and Radian upgrades before sourcing the rest of the components
• Left-Handed Shooters: Builders who require ambidextrous fire controls from the start—the Radian Talon handles the safety, and the Raptor-LT handles the charging handle, both from day one
• Budget-Conscious Quality Buyers: Shooters who refuse to compromise on receiver quality or control group components but want to stretch their build budget further than individual retail pricing allows
• Law Enforcement and Military Builders: Personnel building a personal duty or training rifle who want a mil-spec receiver set with Radian components already included at a package price

Start Your Build the Right Way.

Shield Arms builds every product at our facility in Bigfork, Montana, to the standard that competitive shooters, law enforcement professionals, and serious civilian builders have trusted since day one. The SA-4 Forged Builder Combo puts that standard into a single package—paired with two of the most trusted upgrade components in the AR-15 market—at a price that makes the decision easy. We back the SA-4 lower receiver with our 100% lifetime warranty. The rest of your build is up to you.

Related Products & Accessories

• SA-4 Billet Stripped Lower Receiver — The Billet version of the SA-4 lower on its own, for builders who already have an upper or want to source components individually
• Mil-Standard Complete SA-4 Non-Folding Lower — Fully assembled SA-4 lower with mil-spec trigger, A2 grip, and A2 stock—ready to accept an upper
• Enhanced Complete SA-4 Non-Folding Lower — Fully assembled SA-4 lower with Schmid Tool match trigger, B5 Systems BRAVO Stock, and B5 Systems Type 23 Grip
• Premium Complete SA-4 Non-Folding Lower — Fully assembled SA-4 lower with Schmid Tool match trigger, Radian Talon ambi safety, B5 Systems BRAVO Stock, and B5 Systems Type 23 Grip
• Shield Arms FLR (Folding Lower Receiver) — Shield Arms' patented folding AR-15 lower—the industry's first fully integrated folding lower with no adapter required