Blemished - 80% Lower Fire/Safe Marked - Anodized Black - polymer 80
About this product
The ModFuze blemished anodized black 80% lower receiver is a discounted, fully functional polymer frame blank with minor cosmetic flaws, compatible with standard Mil-Spec components. It is a cost-effective entry point for home builders who prioritize function over finish. These lowers are machined from the same polymer blend and use the same tooling as premium units.
What is the ModFuze blemished 80% lower used for?
This receiver is used as a starting point for building a custom serialized firearm, requiring final machining to 100% completion by the end user. The blemished designation refers only to surface cosmetic imperfections, such as minor tooling marks or storage scuffs, which do not affect structural integrity or dimensional tolerances. It accepts all standard parts kits and is compatible with aftermarket triggers, grips, and buffer systems.
How does the ModFuze blemished lower compare to the Polymer80 PF940V2?
The ModFuze lower is 49% cheaper than a new Polymer80 PF940V2, trading a perfect cosmetic finish for identical functional performance. Where the Polymer80 PF940V2 costs roughly $99, this blemished unit costs $49.99, offering the same rail geometry and magazine well dimensions for less. This makes the ModFuze unit better for budget-conscious builds where appearance is secondary to mechanical function.
What does it weigh and what are the dimensions?
The receiver blank weighs 312 grams (11.0 oz) and measures 135mm in length, 40mm in width, and 90mm in height at its tallest point. This weight is within a 5% tolerance of a standard, non-blemished polymer lower of the same design. The anodized black finish is a standard 25-micron coating, matching most common upper receiver finishes on the market.
Who is this NOT for?
This product is not for first-time builders who anticipate a perfect, showroom-quality finish without additional work. The cosmetic blemishes, while minor, are permanent and will not polish out. It is also not suitable for builds requiring serialized registry with an existing manufacturer's roll mark, as this is a blank receiver without a factory serial number. For a pristine finish, consider the standard Anodized Black 80% Lower.
What's in the box?
You receive one blemished 80% lower receiver blank, packaged in a static-free plastic bag. The box does not include a jig, drill bits, or any tooling required for completion—those must be sourced separately. For a complete kit, review the Best Drill Bits for Polymer Frame Modifications guide.
Is the ModFuze blemished lower worth it at $49.99?
At $49.99, it is worth it for any builder who understands the functional equivalence between blemished and first-quality receivers. The price represents a direct pass-through of cosmetic grading savings to the customer, with no compromise on the critical fire control group pocket dimensions or buffer tower alignment. For the cost of a single magazine, you secure the foundational component of a custom build.
Specs at a glance
Video review
Pros & cons
What works
- Weighs 312 grams (11.0 oz)—identical weight to first-quality units.
- Costs $49.99—49% less than a new Polymer80 PF940V2.
- Matte black anodized 25-micron finish matches most uppers.
- Fire/Safe markings are roll-stamped, not laser-etched, for durability.
Trade-offs
- Cosmetic blemishes are present—small tool marks or scuffs up to 3mm in length.
- No jig or tooling included—adds $60-120 for a proper completion kit.
- Final serialization is owner's responsibility—requires 7-10 day engraving turnaround.
- Polymer construction—less rigid than billet aluminum under sustained fire.
Expert review
Key attributes
| Caliber | Multi (9mm/.40/.357 SIG compatible) |
| Frame Material | Polymer blend |
| Finish | Matte black anodized (25-micron) |
| Condition | Cosmetically blemished |
| Weight | 312 grams (11.0 oz) |
| Compatibility | Glock Gen 3 aftermarket parts |
| Fire/Safe Markings | Roll-stamped |
| Required Completion | 80% to 100% machining by end user |
Specifications
| finish | matte black anodized |
| type | 80% lower receiver |
| condition | cosmetically blemished |
| compatibility | standard (Mil-Spec) parts kits, buffer tubes, grips, magazines, and stocks |
Best for
- DIY firearm building
- receiver blank for custom assembly
Materials
- aluminum
- anodized coating
What's in the box
- blemished 80% lower receiver
Frequently asked questions
- Is it compatible with Glock Gen 3 slides and parts?
- Yes, it is dimensionally compatible with Glock Gen 3 aftermarket slides and OEM-spec internal parts kits. The rail geometry is cut to a 0.5mm tolerance for Gen 3 spec slides. You will need a compatible locking block and rear rail module, typically included in a parts kit.
- Does it fit standard AR-15 buffer tubes and stocks?
- No, this is a pistol-caliber polymer frame for compact builds, not an AR-15 pattern lower. It does not have a buffer tube thread. For a .308 platform, consider the <a href="/products/polymer80-lr-308-80-lower-receiver/">Polymer80 LR-308 80% Lower Receiver</a>.
- How long does shipping take?
- Standard ground shipping takes 5-7 business days from warehouse dispatch for in-stock items. All shipments require an adult signature upon delivery and are processed through regulated carrier networks only.
- Can I return it if it doesn't fit my jig?
- No, all 80% lower receiver sales are final due to federal regulations concerning firearm component transfers. Ensure your jig is designed for polymer 80% frames with a 3-pin design before purchasing. Compatibility details are in the product specifications.
- Does this work with a Slide Fire or binary trigger system?
- The fire control group pocket is cut for standard semi-automatic trigger components. Installation of a binary or forced-reset trigger system depends on the specific trigger manufacturer's compatibility statement and may require modification not covered under warranty.
- What is the warranty coverage?
- The warranty covers manufacturing defects in material or workmanship for one year from date of purchase. Cosmetic blemishes are not considered defects. For precise terms, see <a href="/blog/calculating-polymer-frame-warranty-coverage-limits/">Calculating Polymer Frame Warranty Coverage Limits</a>.