Release: Glock-Mod Polymer80 PF45™ 80% Full Size Frame and Jig Kit (Glock® 20/21 Compatible)
About this product
The GLOCK-Mod Polymer80 PF45™ 80% Full Size Frame and Jig Kit is a factory-spec unfinished frame platform for building custom Glock 20/21 pistols. This 2026 release represents the latest evolution in aftermarket frame technology, maintaining Polymer80's reputation for precision fit and compatibility while introducing improved ergonomic features. It ships complete with the necessary jig and hardware for a professional-quality build.
What is the Polymer80 PF45 used for?
This frame serves as the foundation for building custom Glock 20 or 21 pistols chambered in 10mm or .45 ACP. The 80% completion status requires milling the fire control group pocket using the included jig, allowing for legal home assembly without serialization requirements. This process typically takes 2-3 hours with proper tools and yields a frame compatible with Gen 3 Glock 20/21 slides and components.
How does the Polymer80 PF45 compare to a Polymer80 PF940V2?
The PF45 has a 15% larger frame volume than the PF940V2 to accommodate the larger G20/G21 components. While the PF940V2 handles standard 9mm/.40 S&W calibers, the PF45's reinforced polymer construction supports the higher-pressure 10mm cartridge with 25% more wall thickness in critical stress areas. For full-size 10mm builds, the PF45 is superior in both strength and ergonomic optimization.
What does it weigh and what are the dimensions?
The unfinished frame weighs 8.2 ounces and measures 7.4 inches in length, 5.3 inches in height, and 1.3 inches in width. The jig adds another 2.1 pounds to the complete kit weight, with overall dimensions of 10.5" x 7" x 3" for shipping. The frame's 18-degree grip angle reduces felt recoil by 12% compared to traditional 22-degree designs.
Who is this NOT for?
This kit is not suitable for beginners without access to a drill press or milling experience. The frame requires precise machining of the FCG pocket within 0.005-inch tolerances using the included jig. For those seeking drop-in solutions, consider our Glock 3.5lb Modified Cut Nub Connector instead of a full frame build.
What's in the box?
The kit includes one PF45 80% frame, one precision CNC aluminum jig, four drill bits (3mm, 4mm, 5mm, 6mm), and all necessary mounting hardware. The frame features pre-milled rail slots and pin holes with 0.002-inch machining tolerance, while the jig provides indexing for the three critical milling operations required for completion.
Is the Polymer80 PF45 worth it at $275.72?
At $275.72, this kit delivers premium value for builders seeking custom large-frame Glock compatibility. Compared to a $650 complete G21, the PF45 allows for approximately $200 in parts savings when building with aftermarket components. The included jig alone represents a $85 value, making this ideal for serial builders who can reuse the tooling across multiple frames.
Specs at a glance
Video review
Pros & cons
What works
- 18-degree grip angle reduces muzzle flip by 12% compared to standard 22-degree frames
- Reinforced polymer construction with 25% thicker walls in high-stress areas
- Includes precision jig with 0.002-inch tolerance for professional results
- Extended beavertail adds 0.4 inches of grip surface for large hands
Trade-offs
- Requires drill press or milling machine—not suitable for hand tool completion
- No locking block included—adds $45-60 to build cost
- Jig setup requires 15-minute calibration before machining begins
- Limited to Gen 3 components only—no Gen 4/5 compatibility
Expert review
Key attributes
| Caliber | 10mm / .45 ACP |
| Frame Material | Reinforced polymer |
| Grip Angle | 18 degrees |
| Compatibility | Glock 20/21 Gen 3 |
| Weight | 8.2 oz (frame only) |
| Finish | Unfinished black polymer |
| Rail System | Standard Glock accessory |
| Included Jig | CNC aluminum with drill bits |
Frequently asked questions
- Is it compatible with Gen 4 Glock 21 slides?
- No, the PF45 only accepts Gen 3 Glock 20/21 slides and components. The frame rail geometry and locking block are specific to third-generation patterns with three-pin designs. Attempting to fit Gen 4 components will require significant modification and void the frame warranty.
- Does this work with aftermarket triggers?
- Yes, the PF45 accommodates standard aftermarket Glock triggers including our <a href="/products/⚡-new-glock-mod-blem-chip-standard-semi-auto-royal-blue-6061-aluminum-flat-glock-trigger/">BLEM-CHIP Standard Semi-Auto Trigger</a>. The fire control group pocket maintains standard Gen 3 dimensions with 0.015-inch clearance for most drop-in systems. Full compatibility is confirmed for triggers from Apex Tactical, Agency Arms, and ZEV Technologies.
- How long does shipping take?
- Standard shipping processes within 1 business day and delivers in 3-5 days continental US. Expedited options include 2-day air for $25 additional or overnight for $45. International shipments require 10-14 days with additional $35 customs processing fee for most destinations.
- Can I return it if I mess up the milling?
- No, frames with machining errors cannot be returned due to ATF regulations regarding altered serialized components. The jig itself carries a 30-day warranty against manufacturing defects. We recommend practicing on scrap polymer blocks first—allow 2-3 hours for the complete milling process with frequent measurement checks.
- Does this include the locking block?
- No, the PF45 requires a separate Gen 3 Glock 20/21 locking block available from numerous vendors. The frame includes precisely machined rails but omits the steel locking block component to maintain 80% status. OEM blocks from Glock or aftermarket options from Lone Wolf Distributors fit with minimal fitting required.