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GLOCK 21 Gen 3

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123 documented listings67 fit unconfirmedBrowse categories ↓

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What the compatibility labels mean
How we knowHow we check compatibility
  • Lab testedFit checked by Firearm Lab for the recorded setup.
  • Documented fitmentSupported by manufacturer, partner, or reviewed community evidence.
  • Interface matchMounting details match, but this exact model and part have not been confirmed to fit together.

Check your exact model and part before ordering. Fitment limits

Model details
Manufacturer
GLOCK
Model & version
Glock 21 · Gen 3
Mounting details
Glock Accessory Rail, Glock rear-sight dovetail (standard and Slimline slides)
Compatibility records
190

Sights

Sights

90 listed
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Lights & rail fitment

Lights & Lasers

57 listed
View all 57 parts

Triggers & internals

Triggers

26 listed
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Recoil Springs

4 listed
View all 4 parts

Also on this pistol

Holsters

9 makers

Check each manufacturer’s options for your model, light and optic.

Holster makers (9)

Optics & footprint adapters

Optic Plates

7 listed
View all 7 parts

Barrels & comps

Barrels

3 listed
View all 3 parts

Compensators

1 listed
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Slides

Slides

1 listed
Browse slides

Grip & magwells

Magazines

1 listed
Browse magazines

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Categories with no listings (8)

About the GLOCK 21 Gen 3

Type
Pistol
Manufacturer
GLOCK
Model & version
Glock 21 · Gen 3
Caliber
45 ACP
Mounting details
Glock Accessory Rail, Glock rear-sight dovetail (standard and Slimline slides)

Other versions of the Glock 21

Compare versions and check the details for your exact model.

  • GLOCK 21Same recorded mounting details. Check each part for additional requirements.
  • GLOCK 21 Gen 2Lacks: Glock Accessory Rail.
  • GLOCK 21 Gen 4Same recorded mounting details. Check each part for additional requirements.
  • GLOCK 21 Gen 5Same recorded mounting details. Check each part for additional requirements.
  • GLOCK 21 MOSAdds: Glock MOS. Lacks: Glock rear-sight dovetail (standard and Slimline slides).
  • GLOCK 21 SFSame recorded mounting details. Check each part for additional requirements.
  • GLOCK 21 V MOSAdds: Glock MOS. Lacks: Glock rear-sight dovetail (standard and Slimline slides).