If you want to add a compensator, suppressor, or to build your dream Glock slide. Here are the 5 best Glock 21 threaded barrel upgrades on the market.

These are ranked based on durability, caliber compatibility, and price.

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*Note: Selected barrel may not be legal in all 50 states, please check your local gun laws before purchasing. BadAssOptic.com is not responsible for unlawful possession.

TRYBE Defense Glock 21 Match Grade Barrel - Best Price

TRYBE Defense Grade Threaded Pistol Barrel, Glock 21, .578x28 Thread, Gold TIN, TPBG21-TIN

TRYBE defense Glock 21 match grade barrel offer many different color coating at a good price points. Due to the popularity of this barrel brand, TRYBE Defense products are sold out fast.

This is the best overall aftermarket Glock 21 barrel that is suppressor and compensator ready, to shoot various ammo type included lead.

All threaded barrel from TRYBE defense comes with thread protectors

Caliber - 45 ACP

Thread Pitch - .578x28

Barrel Material - 416R stainless steel

3 Color Options - Gold Tin, Black Nitride, Titanium

Glock G21 45ACP Threaded Barrel, Black, GLSP39895

This is the polygon rifled OEM Glock 21 threaded barrel. Everything is the same as the OEM barrel and it's threaded with a protector ring.

Caliber - 45 ACP

Thread Pitch - 1/2-28 Right hand (Suppressor & Compensator ready)

Barrel Material - 416R stainless steel

Silencer Co Glock 21 Barrel - Best Corrosion Resistant

SilencerCo Threaded Barrel For Glock 17L, 9mm, 6.5 Inch Barrel, .5x28 Threads, Black Nitride Finish, AC861

Silencer CO makes top quality suppressors, and this is their company branded Glock 21 threaded barrel for SilencerCO suppressor users as well as other brands. It features similar specs as other barrels and it's priced very reasonably without breaking the bank.

The lockup tolerance is much tighter, and it works with stock Glock slide or custom slides to ensure accuracy.

Caliber - 45 ACP

Thread Pitch - .578x28

Barrel Material - 416R stainless steel

Lone Wolf Alpha 40mm - Best For Outdoors Protection

10mm glock 21 barrel

This is a great 45 ACP to 10mm conversion barrel for the full size Glock 21 and Glock 20. The barrel is threaded 9/16 x 24, and a thread protector included.

The 10mm cartridge offers a bit more powerful punch than the .45 ACP and it allows has a higher magazine capacity. The overall 10mm's purpose (Before 40 SW was developed) is to have better external ballistics than the 45 ACP, with more power than the 9mm.

Lone Wolf Alpha Wolf - Best 45 ACP Conversion Selections

Lone Wolf Arms Glock 17 9mm Barrel, Raw Stainless, LWD-17TH

Lone Wolf offers many aftermarket Glock barrels. This Glock 21 threaded barrel is built in house with 416R stainless steel to shoot plated, jacked and lead 45 ACP ammo. The SBN coating increases the barrel surface hardness to RC 60, and the barrel flutes creates path for heat dissipation. 

The tolerance is tighter than the OEM barrel, and it's suppressor ready.

Caliber - 45 ACP

Thread Pitch - .578x28

Barrel Material - 416R stainless steel

Glock 21 Barrel FAQ

Why Replace OEM Barrel?

Most people who replace the OEM Glock 21 barrel are for the following reasons:

  • For mounting a suppressor
  • For adding a compensator
  • Improve aesthetics
  • Tighter lockup to increase accuracy (more optimized twist rate)
  • Use button rifling barrel to shoot other ammo type that hex rifling barrels can't

Button Rifling VS Original Glock Polygon Rifling ?

The original Glock hex rifling barrels work well for general purpose use and self defense.

Button rifling barrel allows Glock 21 users to shoot 

Glock 21 Barrel Compatibility 

Glock 21 barrel only fits in Glock 21 slide. It will not fit in other Glock slides.