Glock Chassis and PDW Kits: What to Know Before You Buy

A chassis kit is one of the fastest ways to change what a Glock is. The pistol drops into a frame with a buttstock or brace, a forward grip area and rail space, and you've got a compact PDW style firearm that's dramatically easier to shoot accurately than the pistol on its own.

Three things decide whether it's a good buy: which configuration keeps it legal where you live, whether the kit fits your pistol, and what else you'll need to make it useful.

We checked every Glock PDW chassis on this page against its maker's own fit list on September 27, 2026. Find your pistol in the fit chart before you pick a brand.

Brace or stock: the decision that matters most

A brace keeps it a pistol. The ATF's 2023 rule that would have reclassified many braced pistols as short barrelled rifles was vacated nationwide on June 13, 2024. The Fifth Circuit dismissed the government's appeal on July 25, 2025, after both sides agreed to drop it. Federally, a braced pistol is a pistol today.

ATF proposed deleting the brace language on May 6, 2026. Comments closed August 4, and no final rule had been published when we checked on September 27.

A stock makes it a short barrelled rifle. A Glock barrel is far shorter than 16 inches. The longest one Glock lists is 6.02 in. Fit a stock designed to be fired from the shoulder and you have made an SBR under the National Firearms Act, regardless of what the chassis is called.

The tax on making an SBR went to $0 on 1 January 2026, and on October 9, 2026 ATF stopped enforcing the NFA's registration and its Form 1 and Form 4 approval requirements for SBRs, short barrelled shotguns and suppressors, nationwide.

That followed the August 5, 2026 judgment in Silencer Shop Foundation v. ATF, which blocked those requirements only for the parties it covered. The government didn't appeal, and the Justice Department then extended the same treatment to everyone.

So federally, a stock on a Glock chassis no longer needs a Form 1. Two things still deserve a look first. Some states ban SBRs, and many only allow NFA items that are registered or held in line with federal law. And the policy can be reversed, with no grandfathering for unregistered guns, so an optional Form 1 at $0 is cheap insurance.

Our suppressor guide walks through the same question in detail. Here's the federal paper trail, oldest first.

Until you've checked your state, don't fit a stock to a chassis holding a pistol barrel under 16 inches. Some states ban SBRs or only allow registered ones. A brace avoids the question entirely.

Fit is the part people get wrong

A chassis is built around a frame, not a brand. Recover's 20/20N takes the double stack 9mm and .40 Glocks, and its 20/21 takes the large frame 10mm and .45 models. CAA sells a separate MCK for each family.

Recover's S-Pro covers both through a large frame configuration. The 43X and 48 need their own kit or an adapter: Recover's SA43, or CAA's 43/43X/48 MCK.

We read each maker's compatibility list and its published customer answers on September 27, 2026. Pick your Glock and the chart shows which Glock chassis kits list it. Where the maker hasn't said, you'll see Unconfirmed instead of a guess.

Gen 6 is the gap. We relaunched our Glock builder on September 13. About one Glock in six added to it since is a Gen 6: 11 of 70 Glock pistols added through September 27, 2026, by 10 different builders. That count includes used, Blue Label and Taran Tactical custom Glocks, and leaves out a Fusion clone listed under the Glock brand, the same count our Glock size chart uses. Only one kit's maker says it fits a Gen 6, and that came in a support reply.

Recover's pages also carry catches the fit list doesn't show.

Your light. You'll need to take a pistol mounted light off before the S-Pro goes on. Recover says aftermarket or suppressor height sights may need modifying too.

Gen 6 and the S-Pro. A Recover support reply on September 11 said the S-Pro fits Gen 6 Glocks. Recover's published S-Pro list doesn't name Gen 6, and one line on it excludes Gen 6 frames for the .40 models. We've marked it as a fit with a catch.

Moon cut slides. The S-Pro's charging handle doesn't fit RTF moon cut slides.

Gen 5 .40 slides. The S-Pro frame fits, but the bundled charging handle doesn't. You rack the slide off a red dot instead.

Your 43X slide. The SA43 adapter takes OEM Glock slides only.

Your optic. Recover hasn't tested the Leupold DeltaPoint Micro on the 20/20N, but expects the battery pack to block it.

Budget kit or billet chassis

The two ends of this market are quite different products.

Polymer kits like Recover's 20/20N and the CAA MCK are the budget route. They're light drop in chassis kits that go on in minutes without gunsmithing, and they come with a brace and rail space. They get you most of the experience for the least money. The trade is rigidity: you'll feel more flex and more rattle than in a machined chassis.

Recover lists the 20/20N at $99.95, and you won't need to strip your pistol to fit it. We'd start there. It was in stock at PSA when we checked on September 27. The CAA MCK was out of stock at the one merchant we list, so we've pulled its card.

Recover Tactical

Recover Tactical 20/20N Stabilizer Brace w/ Strap For Glock w/ Low/High Charging Handles - THIS FITS GLOCK MODELS LISTED ONLY

In stock

$99.99 at Sportsmans Outdoor SuperstoreCompare 4 stores+ Add to build

Recover Tactical

Recover Tactical SA43 20/20N Stabilizer KIT for Glock 43/43X/48, Glass-Reinforced Polymer

In stock

$40.46 at Optics PlanetCompare 4 stores+ Add to build

Recover Tactical

Recover Tactical UR20 Upper Optic Mount For Glock 2020/2021 Braces

In stock

$31.99 at Palmetto State ArmoryCompare 5 stores+ Add to build

Own a 43X or 48? The SA43 is an adapter set for the 20/20N, whatever the listing title says, so you need both. Recover sells it for $39.95. The UR20 adds a top rail to the 20/20N, so your dot rides on the kit instead of the slide.

Metal framed and billet chassis are stiffer and usually cost more. The pistol sits more solidly, the optic mounts to something that doesn't move, and the whole thing feels like a firearm rather than an accessory. If you'll use it seriously rather than as a range toy, that's where we'd put the money.

Recover calls the S-Pro a metal frame kit. It isn't billet: one owner's review on Recover's page describes steel at the optic mount and the base, with polymer around it. Recover lists it at $299.95, and CAA lists the MCK 2.0 at $329, so the price gap is smaller than you'd expect. If you've got a Gen 6, the S-Pro is the only kit here with a maker's yes, from a support reply.

Recover's P-IX is glass reinforced polymer and takes a standard AR buffer tube, so you choose the brace. The card below is the PIXB-02, the original tan P-IX with no stock or brace, at about $250. Recover's own site now sells only the P-IX+ at $299.94, which it calls an upgrade on the original.

We took the P-IX row in the fit chart from Recover's own P-IX page, as the Internet Archive saved it in January 2023, before the P-IX+ replaced it.

Put an AR brace on it, not a stock.

Chassis kits barely register in our build data: 4 adds between June 29 and September 27, 2026. Three were this P-IX, and all three came from a catalog page where it's filed under grip tape, so we don't read much into them.

Recover Tactical

Recover Tactical S-PRO Basic Conversion KIT For Glock, Deployable Brace Chassis System, Metal Frame, MLOK Compatible, Black - SPROGB01

In stock

$299.95 at KY Gun CompanyCompare 5 stores+ Add to build

Recover Tactical

Recover Tactical PIXB-02 P-IX AR Platform Conversion KIT (Without Brace) Tan Polymer with Picatinny Mounts for Glock

In stock

$249.95 at Palmetto State ArmoryCompare 3 stores+ Add to build

Folded, these kits stay compact. Here's how each measures up against the bare Glock 19 you may already own, from the makers' own spec pages.

CAA lists the MCK 2.0 at 13.70 in long, 5.70 in high and 2.48 in wide, with no weight published. Recover lists the S-Pro at 13.78 in folded, 21.54 in open and 7.48 in high. A Glock 19 Gen 5 alone is 7.28 in long.

If you own a Ruger RXM. The Reaper we list is JL Billet's RXM Reaper. JL builds it around a Ruger RXM fire control insert, so your Glock frame won't go in it. JL says it takes Gen 3 Glock 17 and 19 slides and Glock magazines.

The Reaper is 9.675 in folded, 18.06 in open and 2 lb built. Neither merchant we list had it in stock on September 27, so we've pulled its card. Our RXM upgrade guide covers what else crosses over.

What it needs to actually be useful

A chassis on its own is mostly a shape. Three additions make it worthwhile.

An optic. The whole point of a PDW configuration is precise shooting further out than a pistol handles comfortably, and a red dot is what delivers it. Mount it to the chassis rail rather than the slide wherever the kit allows, because the slide reciprocates and the rail doesn't.

A light. On anything with a defensive role, identifying your target isn't optional. A chassis gives you rail space a bare pistol doesn't, so use it.

A sling. A shoulder weapon without a sling has to be put down every time you need your hands. A simple two point sling fixes that.

Holosun

Holosun HS507C X2 Red Open Reflex Sight 2MOA/32MOA Circle

In stock

$232.99 at Palmetto State ArmoryCompare 8 stores+ Add to build

Streamlight

Streamlight TLR-1 HL 1000 Lumen Tactical Weapon Light - Flat Dark Earth Brown

In stock

$163.33 at BattleHawk ArmoryCompare 9 stores+ Add to build

Magpul

Magpul MS1 Sling - Coyote Brown

In stock

$30.67 at KY Gun CompanyCompare 7 stores+ Add to build

Magazines

Longer magazines suit a chassis far better than they suit a holstered pistol, because nothing about the configuration needs to conceal. An extended magazine or a basepad extension improves both capacity and the grip you have on the magazine well.

Check your state's capacity limit first. You can carry a spare on the chassis itself: Recover's MG9 holds one at an angle on a Picatinny rail, for the 9mm and .40 kits.

Recover Tactical

Recover Tactical Anglled Forward Magazine Holder for Glock 9/40 w/Picatinny Rail, Black, Small, MG9-01

In stock

$49.46 at Optics PlanetCompare 6 stores+ Add to build

Do not confuse a chassis with a conversion device

We're saying this because the two get mixed up. A chassis changes the shape and handling of a pistol. It doesn't change how it fires, and a Glock in a chassis is exactly as semi automatic as it was before.

A device that makes a Glock fire automatically is a machine gun conversion, a serious federal felony, and nothing to do with any product on this page. Maryland and Connecticut both signed laws on May 26, 2026 against the convertible pistols those devices attach to. A federal judge blocked Connecticut's on September 30, 2026, and Maryland's is still set for January 1, 2027.

What we would actually buy

Answer three questions and the picker lands on a kit that lists your Glock.

Curious, and not sure you'll use it much. A polymer kit with a brace. Recover's 20/20N at about $100 is the cheapest way to find out whether you like the format, and it keeps the legal picture simple.

Serious use. A metal framed chassis with a brace, a quality red dot on the chassis rail, a light and a sling. Budget for the accessories, because they cost more than the kit.

You've got a Gen 6. The S-Pro. Confirm the fit with Recover before you order, since the only word so far is a support reply and the published list doesn't name Gen 6.

You want a stock. Federally you can since October 9, 2026. Check your state's SBR rule first, and consider an optional Form 1 in case the policy is reversed.