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Some Assembly Required: PF940Cv1 80% Compact Glock Frame

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The PF940Cv1 80% Compact Glock Frame — Some Assembly Required

Compact Polymer80 frame? Why, yes please — and here's why.

Back in RECOIL Issue 28 we completed one (well, several) full size 80% Glock receivers from Polymer 80. If you don't happen to have that issue, the entire article can be found online right here. So naturally, when the compact frame versions were announced, we knew we'd have to get our hands on one. Polymer80 is making two different versions, the PF940Cv1 and the PF940Cv1 ReadyMod. Each model comes with significant upgrades of the sort many people send off their OEM Glock slides for; while the standard comes with aggressive texturing, the ReadyMod comes smooth for your own easy customization.


Far from just shrinking down their full size Spectre, Polymer80 calls the PF940Cv1 a complete redesign–and they're not lying. Check out the comparison for yourself:

The machining is also slightly different, as you can see from both the jigs and the included tooling


To complete the Spectre, we found that clamps were needed to keep the jig on tightly. The compact model now has a locking tab on top to help keep everything tighter. Though we still ended up using a clamp on the bottom, it was a large improvement. Probably the single largest improvement between the two as far as ease of finishing is the inclusion of metal rails for the rear of the frame. By far the most tedious task with the Spectre was cutting and squaring the plastic rails–plus they didn't exactly inspire confidence in many end users due to the OEM frames having all-metal rails.

Gone also are the screws for the locking block, instead opting for a steel pin. The rear housing is also held in place with a steel, rather than plastic, pin.


As with the full size version, we opted to use a drill press in conjunction with a small bench vise for the milling operations. Instead of one large area to mill, there are two smaller areas.

Learning our lessons from the previous build (because it's certainly not due to an increase in skill), the holes in the frame itself were made with a cordless drill and a level as opposed to the drill press. Six different holes were made (three on each side) as opposed to completely drilling through all in one go.

After that it's just test fitting the frame inserts. Of course and as usual, it's much easier to take away material than to add any. Like with the Polymer80 Spectre, you're going to need some parts to completely finish the PF940Vc1:

  • Complete slide assembly, including barrel and recoil spring
  • Trigger and trigger bar
  • Rear housing assembly, including trigger spring, ejector in appropriate caliber, and connector
  • Magazine catch and spring
  • Slide stop lever
  • Slide locking lever and spring
  • Pins (trigger, locking block, but not the rear housing assembly pin)

Most of the small parts are completely interchangeable with a full size Glock, with the notable exception of the slide lock spring.

At the Range

The completion of the PF940Cv1 itself proved to be very straightforward. Heading to the range we were pretty confident that it would be running with no issues and that (thankfully) turned out to be true. We ran both OEM and aftermarket slides, barrels, and springs without even a hint of malfunctions or sluggish operation. We once heard that no gun you build will truly work until you get some of your blood on it, and due to a slip of the hand this sacrifice was inadvertently made.

Obviously it's the blood and not our machining prowess that made the success of this build possible.



Upgrades Over OEM

The Spectre offered some ergonomic improvements for some compared to a standard Glock 17 frame such as a beavertail, larger grip, and integral magwell, but it's very evident that the folks at Polymer80 went further with the PF940Vc1. They took those critiques and criticisms, as well as looking hard at the aftermarket, to offer up “custom” right out of the box. Though many complain that finishing a Glock 17 frame is more expensive than simply buying an OEM model on Gunbroker — we require no such excuse to build an 80% lower for the fun of it — the PF940Vc1 has advantages you'd pay a lot of extra money for.

Let's start with the texturing.


The magazine release bevel is also excellent. If you're the type to use extended releases, you may not require one here.


You'll notice the distinct “Glock 19” shaped magwell instead of a large flared one like the Spectre.


This is no accident, because if you have an aftermarket magwell that you like for your Glock 19 — it'll fit on here too.

Other differences between an OEM frame include a full Picatinny rail, lack of finger grooves, undercut trigger guard, a “gas pedal”, and slightly more upright grip

A noteworthy feature is a little embedded metal tab for engraving under the accessory rail. While this may seem unnecessary for the home builder, it really opens up manufacturers to start churning out their own frames to go with their custom slides. You'll likely see completed frames available on the market very soon.

So How About Holsters?

In the wide world of custom Kydex, a holster is probably just an email away–but what about what you already have? We tried several, and needless to say not all of them worked out.

Light-bearing holsters may be a different story, however. Because holsters that can accommodate a WML usually secure on the light itself, we had some better luck there.

The Safariland Pro-Fit GLS Holster did live up to its “universal” moniker, as you can see.



In the end, so long as you don't muck up the last 20% of this 80% lower, the juice does appear to be worth the squeeze. It's a fun afternoon project and you get a whole slew of custom features right from the word go. You can use the PF940Vc1 with an OEM slide for something a little different, or you can go full-boat aftermarket.

It's like a range-worthy Choose Your Own Adventure book and a good excuse to use some power tools.


You can visit Polymer80 online here, but it's noteworthy that these frames are only available from authorized distributors and not directly from Polymer80.



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