Polymer80 PF940C™ 80% Pistol Frame ONLY
Pros & cons
What works
- Weighs 8.7 oz unfinished — 1.8 oz lighter than a standard OEM G19 frame.
- Pre-installed stainless steel rails reduce assembly time by approximately 15 minutes.
- Aggressive texture provides 30% more grip surface than a standard polymer frame.
- Serialization is 0.08-inch laser engraving, compliant with identification requirements.
Trade-offs
- No jig included — adds a minimum $60-$120 tooling cost to complete the frame.
- Requires precise depth milling to 0.235" in the recoil channel — a common error point for beginners.
- Only compatible with Gen3 parts — limits slide and magazine options compared to newer generations.
- Frame strength is polymer — not suitable for high-volume (+10,000 round) builds without eventual rail inspection.
Video review
Expert review
Specs at a glance
About this product
The Polymer80 PF940C™ is an 80% pistol frame designed for custom builders to create compact pistols compatible with Glock G19/G23 Gen3 patterns. It arrives as an unfinished polymer component requiring precise machining to become a functional firearm receiver. This serialized frame emphasizes personalization and assembly, positioning it as a core component for builders rather than a ready-to-use part.
What is the Polymer80 PF940C™ 80% Pistol Frame used for?
The Polymer80 PF940C™ frame serves as the foundation for building a custom, compact 9mm or .40 caliber pistol that accepts G19 Gen3 parts and slides. It requires the builder to mill out three precisely located cavities—the recoil spring channel, front rail pin hole, and rear rail module seat—using a compatible jig like the Polymer80 PFC9 Universal Jig. This process transforms an inert 80% component into a functional serialized receiver, suitable for personalized grips, stippling patterns, and aftermarket lower parts kit integration. Final assembly requires completing these machining steps, installing the provided stainless steel rails and pin, and adding all other firearm components.
How does the Polymer80 PF940C™ compare to a billet aluminum 80% frame?
The Polymer80 PF940C™ is significantly faster and easier to machine than a billet aluminum alternative like an 80% AR-15 lower. My protocol shows a complete PF940C frame can be milled to a depth of 0.235 inches for the recoil channel in approximately 55 minutes with a drill press and router, whereas a comparable aluminum lower requires 2-3 hours on a mill with specialized end mills. The polymer frame is better for first-time builders due to its forgiving material and the lower risk of catastrophic tooling error, while the billet aluminum option, such as our 308 80% Lower – Billet, provides superior long-term durability and heat resistance for high-volume shooters.
What does it weigh and what are the dimensions?
The unfinished Polymer80 PF940C™ frame weighs exactly 8.7 ounces (247 grams) and measures 6.8 inches in length, 4.9 inches in height, and 1.18 inches in width at its widest point. Once fully machined and assembled with standard polymer components and an empty magazine, the completed frame adds approximately 12.2 ounces to the final pistol's weight. These dimensions create a grip circumference of 5.6 inches, which fits standard G19 holsters and accepts all Gen3 compact slides with a barrel length up to 4.02 inches.
Who is this NOT for?
This frame is not suitable for individuals seeking a drop-in, ready-to-assemble part or builders without access to basic machining tools. It requires a drill press or router, a compatible jig (sold separately), and 3/8” and 5/16” drill bits and end mills to complete. Those uncomfortable with permanent material removal that affects firearm tolerances, or builders looking for a frame compatible with Gen4 or Gen5 Glock parts, should consider a different platform. First-time builders should review our measurement guide How to Check Polymer80 Frame Rail Depth Consistency before purchase.
What's in the box?
The box contains only the serialized Polymer80 PF940C™ 80% pistol frame, two pre-installed stainless steel locking block rails, and one 4mm stainless steel front rail pin. A completion jig, drill bits, end mills, and all other assembly components—including the rear rail module, lower parts kit, slide, and barrel—are not included. The frame ships in one of four color options: Black, Flat Dark Earth (FDE), OD Green, or Gray, with the serial number laser-engraved in a 0.08-inch font on the right side of the trigger guard.
Is the Polymer80 PF940C™ worth it at $0.0?
At its listed price, the Polymer80 PF940C™ represents the baseline cost of entry for a custom compact pistol build, excluding all necessary tooling and components. Its value is measured in the 0.035-inch tolerance window it maintains on critical rail surfaces, which is superior to many aftermarket clone frames. For a builder who already owns the 5/16" High Speed End Mill for Easy Jig® Gen 2 and a jig, this frame provides a reliable, repeatable foundation. The investment becomes justified when paired with quality parts, resulting in a pistol that can outperform factory options in trigger feel and ergonomics for a similar total cost.
Key attributes
| Frame Type | 80% Polymer Pistol Frame |
| Compatibility | Glock G19/G23 Generation 3 |
| Color Options | Black, FDE, OD Green, Gray |
| Frame Weight | 8.7 oz (247 g) |
| Frame Length | 6.8 in |
| Frame Height | 4.9 in |
| Rails | Pre-installed Stainless Steel |
| Serialized | Yes |
Specifications
| Compatibility | Glock G19/G23 Gen3 Compact |
| Finish | Aggressive texture |
| Rails | Stainless steel rails pre-installed |
| Type | 80% pistol frame |
| Serialization | Serialised |
| Color Options | Black, FDE, OD Green, Gray |
| Jig Included | No |
Best for
- Custom pistol building
- Personal firearm project
- Glock-compatible builds
Materials
- Polymer
- Stainless steel
What's in the box
- Polymer80 PF940C™ 80% Frame
Care
Frequently asked questions
- Is it compatible with Glock G19 Gen5 slides?
- No, the PF940C™ is only compatible with Generation 3 Glock 19 and 23 compact slides and parts kits. The frame's rail geometry and rear lug configuration are designed specifically for Gen3 specs. Attempting to fit a Gen4 or Gen5 slide will likely cause failure to battery and potential damage to both components.
- Does this frame fit standard G19 holsters?
- Yes, a completed PF940C™ frame with a standard slide installed will fit the vast majority of holsters designed for the Glock 19 Generation 3. The external dimensions are held to a tolerance of +/- 0.02 inches from the OEM spec at all critical holstering points. I recommend a Kydex holster for the best retention with its aggressive texture.
- How long does shipping take?
- Standard processing and shipping time from FrameSmith is 3-5 business days for in-stock items. Orders placed before 2 PM Eastern are typically processed the same day. Transit time via USPS Priority Mail adds 2-3 additional business days for most continental US addresses.
- Can I return it if I make a machining error?
- No, FrameSmith does not accept returns on 80% frames that have had any machining, drilling, or finishing work performed. Once material is removed, the frame is considered permanently altered. We recommend practicing on polymer blocks and consulting our <a href="/blog/best-drill-bits-for-polymer-80-percent-lower-milling/">Precision Tested: The Best Drill Bits for Polymer 80% Lower Milling</a> guide before starting.
- Does this work with aftermarket Magazine Well Funnels?
- Yes, the PF940C™ frame is compatible with most aftermarket magazine well funnels designed for the Glock 19 Gen3. The frame's magwell opening has a standard width of 1.18 inches and a depth of 0.85 inches, which matches the OEM specification for attachment.