Dimensions of muzzle threads on firearms

The list of thread dimensions below contains the information published by manufacturers, i.e., it applies to factory-made barrels. The list is for information only, the muzzle thread dimensions may differ depending on the development of the product and changes in the course of its production. We recommend always measuring the thread size on a particular firearm.

Firearms based on the AR15 platform

The standard dimension of threads on AR15 barrels (.223 Rem) is 1/2″x28, but this can differ with some manufacturers – for example, Heckler & Koch uses the M15x1 thread. A special case is the SIG firearms, where the thread is standard (MCX – 1/2×28, MPX – 13.5x1L), but it is terminated with a specific taper (Sig Taper); for these we recommend a professional modification of the thread insert.

Firearms based on the AK platform

The standard dimension of the muzzle thread on the AK 47, AKM and their clones (7.62×39) is 14x1L, while the thread used for the AK 74, AKSU, AK100 platforms and their clones is usually 24×1.5, and for the firearms produced in Romania it is 22×1.5. We recommend measuring the thread dimension before making a purchase.  


CZ (Česká zbrojovka)

CZ P-10 C – 1/2″x28


CZ SCORPION EVO 3 S1 a A1 – M18x1

CZ 457 – 1/2″x20

CZ 512 Tactical  – 1/2″x28

CZ 527 7,62×39 – M15x1

CZ 527 .223 Rem (Except THUMBHOLE) – M14x1

CZ 527 Thumbhole .17 Hornet, .223 Rem – M15x1

CZ 557 (Except VARMINT) – M14x1

CZ 557 VARMINT – M18x1

CZ BREN 2 .223 Rem – 1/2″x28

CZ BREN 2 7,62×39 – M14x1L

CZ BREN 2 a CZ 807 military models – M14x1L

CZ BREN BR 7,62×51 – 15×1

CZ 858, Vz.58 7,62×39 – M14x1


All 9mm models except the slim series (G43, etcM13,5x1L (older models had the 13×1 threads)

All .45 ACP models – M16x1L

Glock 42, 43, 43X – M12x0,75

Glock 44 (.22 LR) – M9x0,75


9mm Glock models  – 1/2″x28