Polymer80 PF940C™ 80% Pistol Frame ONLY - polymer 80
Pros & cons
What works
- Weighs 9.8 oz raw — provides a lightweight base for a compact carry build.
- 84% pre-formed — includes molded grip texture and pre-cut recoil spring channel, saving an estimated 30 minutes of milling work.
- Gen 3 G19 compatibility — accepts the widest ecosystem of aftermarket slides and parts kits on the market.
Trade-offs
- No rear rail module included — adds a $40-60 mandatory purchase and critical fitting step that dictates build success.
- Requires a separate, specific jig (P80-JIG-PF940C) — an additional $50-80 tooling cost not reflected in the frame price.
- Zero warranty coverage — as an 80% item, it carries no factory guarantee once any machining is performed, as outlined in our warranty guide.
Video review
Expert review
Specs at a glance
About this product
The Polymer80 PF940C™ 80% Pistol Frame ONLY is the core, unserialized polymer chassis designed for hand-fitting slide components to build a G19-generation compact pistol. It arrives at 84% completion, having been injection molded and having the recoil spring channel pre-formed, requiring you to perform the remaining 16% build process to create a functional firearm. This process is a deliberate technical exercise, not an off-the-shelf solution, which carries significant legal and technical responsibilities for the builder.
What is the Polymer80 PF940C™ 80% Pistol Frame ONLY used for?
This 80% frame is used exclusively as a project component for building a compact, Glock 19-sized pistol. Its primary function is to serve as the legal starting point that you, the builder, machine and assemble into a functioning handgun frame, assuming full responsibility for its creation and compliance. The frame's dimensions and internal geometry are engineered to accept aftermarket Gen 3 Glock 19 slides, barrels, and lower parts kits once the rear rail module is installed and pin holes are drilled. This procedure requires specialized tools like a drill press or router jig, detailed in our guide on the best drill bits for polymer frame modifications.
How does the Polymer80 PF940C™ compare to the ModFuze .308 80% Lower – Billet?
The Polymer80 PF940C is better for building a compact pistol, while the ModFuze .308 80% Lower – Billet is superior for constructing a precision rifle platform. The PF940C is a 100% polymer frame weighing approximately 9.8 ounces in its raw state, designed for handgun components. In contrast, the .308 80% Lower – Billet is milled from 7075-T6 aluminum alloy and weighs nearly 2.1 pounds, engineered to handle the significantly higher pressures and stresses of a rifle cartridge.
What does it weigh and what are the dimensions?
The raw, unmachined frame weighs 9.8 ounces (278 grams) and has external dimensions of 7.28 inches (185 mm) in length, 1.26 inches (32 mm) in width, and 5.04 inches (128 mm) in height. These figures are taken prior to any drilling, milling, or installation of components. After a complete build with a standard polymer magazine, the assembled frame's weight typically increases to between 22 and 24 ounces, depending on your choice of magazine and internal parts.
Who is this NOT for?
This frame is not for anyone seeking a pre-assembled, ready-to-use firearm or who is unfamiliar with federal and state laws regarding homemade firearms. It requires a clear understanding of legal definitions, such as the point at which an unfinished receiver becomes a firearm per the ATF. It is also unsuitable for builders without access to proper fixtures like a vice and a drill press capable of stable operation between 800-1200 RPM, as poor tooling leads directly to out-of-spec pin holes and malfunctioning safety mechanisms.
What's in the box?
You receive only the single, 80% complete Polymer80 PF940C frame. The box does not include a rear rail module, locking block, drill bits, a jig, pins, or any lower parts kit—these are all separate purchases critical for completion. This contrasts with kits like the see Polymer80 80% Lower Receiver and Jig Kit (LR-308), which bundles the necessary tooling. You must source the rear rail system separately, a component whose alignment directly impacts slide-to-frame fit and is the subject of our technical article on compared here: adjusting slide stop tension.
Is the Polymer80 PF940C™ worth it at $160.99?
At $160.99, its value is tied directly to your technical intent and the current market scarcity of such unfinished frames. The price reflects its status as a legacy product in a constrained market, not necessarily its material cost. When evaluating, consider the additional $100-150 required for a quality rear rail module and jig, plus another $250-400 for a complete lower parts kit and slide assembly. For a builder focused purely on the technical challenge of creating a compact pistol from near-scratch, it provides the essential platform. For someone wanting a functional firearm with less complication, a serialized frame or complete pistol is a more direct and often more legally straightforward expenditure.
Key attributes
| Caliber | 9mm (via compatible slide/barrel) |
| Frame Material | Glass-filled polymer |
| Compatibility | Glock 19 Gen 3 components |
| Frame Finish | Molded black polymer |
| Completion State | 80% (unmachined) |
| Weight (Raw) | 9.8 oz (278 g) |
| Condition | New, unfinished |
Frequently asked questions
- Is this frame compatible with Gen 5 Glock parts?
- No, the PF940C frame is designed exclusively for Gen 3 Glock 19 compatible components. Key incompatibilities include the different recoil spring assembly design and trigger mechanism housing of Gen 4 and Gen 5 models. You must source all slides, barrels, and internal parts kits specifically marked for Gen 3 compatibility.
- Does it come with the required rear rail module?
- No, the rear rail module is not included. It is a critical, separate component you must purchase, typically from a third-party vendor like Rook Tactical or P80Rails. Proper installation of this module dictates slide alignment and feed reliability, adding approximately $40-60 and an hour of precise fitting work to your total build.
- What jig do I need to complete it?
- You need a Polymer80 PF940C-specific drill/jig fixture, sold separately under part number P80-JIG-PF940C. Using an incorrect or universal jig will result in misaligned pin holes, likely rendering the frame non-functional. The correct jig provides the necessary 3/8" drill stop for the trigger and locking block pin holes.
- Does this work with aftermarket magazine releases?
- Yes, it accepts standard Gen 3 Glock 19 magazine release components and their aftermarket equivalents. The frame has a pre-molded cavity for the magazine release spring and channel. Installation typically requires a flat-head punch and takes about 90 seconds once the frame is fully machined and the pin holes are cleared.