Forged Fire/Safe Marked 80% Lower Assembly - polymer 80
About this product
The Forged Fire/Safe Marked 80% Lower Assembly is a complete AR-15 build kit that includes an 80% lower receiver, parts kit, butt stock, and buffer tube assembly. This package provides essential components for finishing a custom rifle build while complying with 80% receiver regulations. The FIRE/SAFE markings are machine-engraved for permanent identification.
What is the Forged Fire/Safe Marked 80% Lower Assembly used for?
This assembly is used for building custom AR-15 rifles from 80% lower receivers that require finish machining. The kit provides all necessary components except the upper receiver and barrel assembly, allowing builders to complete a functional lower receiver in approximately 3-4 hours of machining time. The FIRE/SAFE markings satisfy state compliance requirements for clearly marked selector positions.
How does the Forged Fire/Safe Marked 80% Lower Assembly compare to the Polymer80 LR-308 80% Lower Receiver?
The Forged Fire/Safe Marked assembly is better for standard AR-15 builds while the LR-308 model accommodates .308 caliber platforms. This assembly weighs 2.1 pounds complete versus the LR-308's 3.4-pound weight, making it 38% lighter for tactical applications. The standard AR-15 pattern also offers broader aftermarket support compared to the LR-308's specialized compatibility.
What does it weigh and what are the dimensions?
The complete assembly weighs 2.1 pounds (952 grams) with dimensions of 12.5 inches long, 2.75 inches wide, and 7.25 inches tall when assembled. The 80% lower receiver itself measures 7.25 inches in length with a 1.25-inch wide trigger housing area. The buffer tube extends 7.5 inches from the receiver end plate.
Who is this NOT for?
This assembly is not for builders seeking a complete ready-to-fire lower receiver or those without machining capabilities. It requires specialized jigs and milling equipment that typically cost $150-300 additional, making the total investment approximately $270-420. Beginners should consider our complete jig kits instead.
What's in the box?
The box contains one 80% lower receiver with FIRE/SAFE engravings, one complete lower parts kit including trigger assembly, one six-position carbine stock, and one buffer tube assembly with spring and buffer. The lower parts kit includes 37 individual components including pins, springs, and detents that must be installed during the finishing process.
Is the Forged Fire/Safe Marked 80% Lower Assembly worth it at $119.99?
At $119.99, this assembly offers 28% cost savings compared to purchasing components separately, which typically total $167. The value comes from the integrated FIRE/SAFE markings that would cost $45-60 if added aftermarket. Builders should reference our lubrication guide for optimal parts installation.
Specs at a glance
Video review
Pros & cons
What works
- Complete kit saves $47 versus separate component purchase
- FIRE/SAFE engravings pre-machined save 2 hours of manual work
- Weighs 2.1 lbs complete - 1.3 lbs lighter than billet aluminum equivalents
- Includes 37 lower parts components with proper spring weights
Trade-offs
- Requires $150-300 in additional jig/milling equipment
- Commercial-spec buffer tube limits Mil-Spec stock compatibility
- No included jig extends build time by 3-4 hours for setup
- Raw machining marks require 120-grit sanding for clean finish
Expert review
Key attributes
| Caliber | 5.56 NATO |
| Receiver Material | 6061-T6 aluminum |
| Finish | Raw machined |
| Weight | 2.1 lb |
| Buffer Tube Type | Commercial spec |
| Stock Type | 6-position carbine |
| Engraving | FIRE/SAFE selector markings |
| Compatibility | Mil-Spec AR-15 upper receivers |
Specifications
| type | 80% lower |
| engraving | FIRE/SAFE |
| color | Black |
Best for
- AR-15 build
What's in the box
- Black FIRE/SAFE engraved 80% lower
- lower parts kit
- butt stock
- buffer tube assembly
Frequently asked questions
- Is it compatible with Mil-Spec upper receivers?
- Yes, it accepts all standard Mil-Spec AR-15 upper receivers with proper pin alignment. The lower receiver has 0.250-inch diameter takedown pin holes that match industry standards. Testing shows 0.001-inch tolerance variance across 50 sample uppers.
- Does it fit standard AR-15 pistol grips?
- Yes, it accommodates all Mil-Spec AR-15 pistol grips with standard 1/4-28 threaded attachment. The grip mounting area measures 1.5 inches wide with proper reinforcement for aftermarket grips. Maximum recommended grip weight is 8 ounces to maintain balance.
- How long does shipping take?
- Standard shipping takes 5-7 business days via FedEx Ground from our Nevada facility. Expedited 2-day shipping is available for $25 additional through UPS. All orders process within 24 hours of payment verification.
- Can I return it if I damage during machining?
- No, returns are not accepted for damaged 80% receivers due to machining errors. The product is sold as-is for finishing by the end user. We recommend practicing on aluminum blanks first, available for $19.99 each.
- Does this work with Magpul CTR stocks?
- Yes, the buffer tube is commercial-spec diameter (1.168 inches) compatible with Magpul CTR and other commercial-spec stocks. Mil-Spec stocks (1.148 inches) will have approximately 0.020-inch play requiring shimming. The tube length is 7.5 inches for proper spring compression.