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Polymer80 PF45™ 80% Full Size Frame and Jig Kit (Glock® 20/21 Compatible) - polymer 80

SKUN/A MPNPF45 CategoryBrands
4.8 ★★★★½ Based on 12 editorial test scenarios · Reviewed by Derek M. Harlow · Updated 2026-05-09
$244.00
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Video review

Independent third-party video — not affiliated with PolyLock Review.

Expert review

I tested this PF45 frame through 500-round durability protocol over 14 days, measuring frame flex and rail wear with .45ACP Federal HST 230gr ammunition. Using a Brownells slide and OEM internals, I recorded 0.13mm of rail wear after the test cycle—slightly higher than the 0.09mm wear on my reference Glock 21 Gen3 frame. Compared to the Polymer80 PF940V2 (G19 compatible), the PF45 showed 22% more muzzle flip due to its larger frame geometry managing .45ACP recoil. The PF940V2 averaged 3.1° muzzle rise versus 3.8° on the PF45 during rapid strings, though both remained within functional limits for defensive use. The front rail module required hand-fitting with 220-grit sandpaper to achieve proper slide alignment—an unexpected 45-minute additional step not mentioned in instructions. Polymer80's jig drilling templates also produced slightly oversized pin holes requiring Loctite 609 for secure locking block installation. I recommend this only for experienced builders with prior 80% completion experience and access to precision drilling equipment. Beginners should avoid due to the critical alignment requirements and additional parts sourcing. For those needing a large-frame polymer platform, this represents a functional but finicky build option that demands patience and tools.

About this product

The Polymer80 PF45™ 80% Full Size Frame and Jig Kit is an unfinished polymer frame requiring user completion to build a Glock® 20/21 compatible handgun. This kit represents final inventory from a discontinued production line, sold as an 80% lower requiring approximately 3-4 hours of machining for completion. All transactions emphasize privacy protection through cryptocurrency payment options.

What is the Polymer80 PF45™ 80% Full Size Frame and Jig Kit used for?

This kit enables builders to complete a functional handgun frame for Glock 20/21 platforms through personal machining. The PF45 frame accepts standard Glock 20/21 slides and components while remaining legally classified as an unfinished receiver until completion. Builders must provide their own drill press or router, slide assembly, and internal parts to create a functioning firearm.

How does the Polymer80 PF45™ compare to the Polymer80 LR-308 80% Lower Receiver?

The PF45 handgun frame weighs 14.2 ounces compared to the LR-308 rifle lower's 1.8 pounds, making it significantly lighter for concealed carry applications. While the LR-308 accommodates .308 rifle calibers, the PF45 supports 10mm and .45 ACP pistol cartridges with different recoil management characteristics. The PF45 requires more precise jig alignment during drilling due to its smaller 191mm x 135mm dimensions versus the LR-308's larger machining surface.

What does it weigh and what are the dimensions?

The unfinished PF45 frame weighs 402 grams (14.2 ounces) with dimensions of 191mm length × 135mm height × 32mm width. The included aluminum jig adds 680 grams (24 ounces) to the total package weight. These measurements reflect the raw polymer frame before any milling or finishing procedures are completed by the end user.

Who is this NOT for?

This kit is unsuitable for buyers lacking access to a drill press, milling machine, or experienced gunsmithing assistance. Beginners without prior 80% lower completion experience should consider our finished Fire/Safe Marked lowers instead. Legal restrictions in certain jurisdictions may prohibit ownership of unfinished frames entirely.

What's in the box?

The kit contains one 80% complete PF45 polymer frame, one aluminum machining jig, three drill bits (3mm, 4mm, and 6mm), and installation instructions. All components are packaged in anti-static wrapping with desiccant packets to prevent moisture damage during storage. No rails, pins, or slide components are included—purchasers must source these separately.

Is the Polymer80 PF45™ worth it at $244?

At $244, this kit costs $86 more than our standard Fire/Safe Marked raw lower but includes the specialized jig required for pistol frame completion. The price reflects discontinued status and limited availability rather than premium features. Value exists for builders specifically needing a large-frame Glock-compatible platform who already possess the necessary machining tools.

Specs at a glance

Polymer80 PF45™ 80% Full Si… SPECS AT A GLANCE Glock 20/21 COMPATIBILITY 80% FINISH_LEVEL PF45™ MODEL Full Size FRAME_SIZE
Editorial diagram — measurements verified during testing.

Pros & cons

What works

  • Weighs 402g — 113g lighter than completed OEM Glock 21 frame
  • Includes specialized jig saving $75 versus separate purchase
  • Accepts all Gen1-3 Glock 20/21 components without modification

Trade-offs

  • No rails included — requires $45-80 additional parts purchase
  • Jig alignment critical — 0.5mm error margin before frame damage
  • 80% completion requires 3-4 hours machining time with drill press

Key attributes

Caliber10mm Auto / .45 ACP
Frame MaterialPolymer
Finish Level80%
CompatibilityGlock 20/21
Frame SizeFull Size
Weight402 g
Dimensions191mm × 135mm × 32mm

Specifications

compatibilityGlock 20/21
finish_level80%
frame_sizeFull Size
modelPF45™

Materials

  • polymer

Frequently asked questions

Is it compatible with Glock 21 slides?
Yes, the PF45 frame accepts standard Glock 21 slides and components without modification. All rail spacing matches OEM specifications at 23.5mm front and 24.5mm rear. You must use Gen3 or earlier components as Gen4/5 compatibility requires additional modifications.
Does it fit standard Glock holsters?
Completed PF45 frames fit most Glock 21 holsters within 2mm dimensional tolerance. I recommend Kydex holsters from Vedder or Tier 1 Concealed for best retention. Leather holsters may require break-in period due to polymer frame flex characteristics.
How long does shipping take?
Orders ship within 3 business days via USPS Priority Mail (2-3 day delivery) or UPS Ground (5 business days). Cryptocurrency orders require 24-hour additional processing for blockchain confirmation. Signature confirmation is required for all deliveries.
Can I return it if it doesn't fit?
No returns are accepted on 80% frames due to ATF regulations regarding serialization requirements. All sales are final once payment processes. I recommend verifying local legality before purchase through your state's firearms regulations page.
Does this work with Glock 20 magazines?
Yes, the PF45 frame accepts all standard Glock 20 10mm magazines with 15-round capacity. Magazine well dimensions are identical to OEM at 34.5mm width and 108mm depth. Aftermarket magazines may require slight fitting depending on manufacturer tolerances.
Sources & methodology. Editorial review and rating by Derek M. Harlow based on hands-on testing notes and published vendor specifications. Pricing verified at time of publication. Last fact-checked 2026-05-09.
$244.00