# Barrel threads

In firearms, barrel threads refer to the screw threads used to attach a barrel.
Action threads, also called receiver threads, are situated at the chamber end of the barrel, and can be used for attaching the barrel to the receiver. The receiver normally has corresponding threads which are internal, with the matching action threads on the barrel usually being external threads. This design is most commonly used in rifles and revolvers, but also on some pistols and shotguns. This method of fixing a barrel to a receiver has been used extensively by firearms manufacturers since before the 20th century, and can be viewed as a traditional barrel mounting method. Action threads are not the only method of fixing a barrel to a receiver (see Alternative methods below). Furthermore, recoil-operated firearm designs have moving barrels (e.g. most pistols or the Barrett M82 rifle).
Muzzle threads are situated at the muzzle end of the barrel and can be used for mounting accessories such as a flash hider, suppressor or muzzle brake (compensator).

## Designation

There are many systems for designating thread types (metric, unified, Whitworth, etc.). Threading can be specified by diameter, pitch, angle, length and fit tolerances. However, the use of action threads is not well standardized within the firearms industry, and threading can vary between manufacturers and models.
For example, factory and aftermarket receivers using the Remington 700 footprint are produced with various types of action threads, all with a 26.99 mm (1+1⁄16 in) diameter, but with a pitch of either a 1.588 mm (16 TPI, Remington standard), 1.411 mm (18 TPI) or 1.270 mm (20 TPI, Savage standard).
Typically, many rifles use thread diameters in the range between 25–27 mm (0.98–1.06 in). Many older rifles from the first half of the 20th century use a thread pitch around 2 mm (12.7 TPI), while many modern rifle use thread pitches around 1.5 mm (16.93 TPI). Fine threaded systems intended for hand tightening typically use thread pitches around 1 mm (25.4 TPI).

## Mounting

Using action threads to mount a barrel to a receiver typically requires fitting by a competent gunsmith, and typically some machining has to be done.
In this process it is important so set the correct headspace. Correct mounting is important both for safety and accuracy. If the barrel, receiver and bolt are not fitted properly, severe and potential fatal problems can arise due to faulty headspace, e.g. cartridge overpressure and case rupture. Threaded barrels are often mounted to the receiver with a lot of torque, and will therefore generally require tools for assembly and disassembly, such as a suitable action wrench and a vise. Depending on the firearm, a recoil lug is sometimes fitted between the barrel and stock as part of the process,
Cleaning up the receiver and barrel action threads is often done during "blueprinting" in order to increase accuracy.

## Action threads
### List of action threads

* M designates common V threads (like for instance metric threads)
* Sq designates square threads
* Tr designates trapezoidal threads
* The shank length is not always the same at the thread length, which is the case if the insert has a threadless portion (sub-shank)
* Tenon designates the thread length
* Shoulder designates the barrel diameter in front of the thread portion
* Unless otherwise mentioned, right hand threads are assumed. Left hand threads are designated "LH".
| Model | Diameter (mm) | Pitch (mm) | Thread angle | Shank length | Comment | Inch |
| Smith & Wesson J Frame | M12.70 | 0.706 mm | 60° | | Also written as 0.500"-36 | 1/2"-36 |
| Smith & Wesson K Frame | M13.72 | 0.706 mm | 60° | | Also written as 0.540"-36 | 69/128"-36 |
| Smith & Wesson L Frame, Colt J, V, Colt AA Mark III / King Cobra, Colt Python (new), Colt Trooper (J, V, AA) | M14.27 | 0.706 mm | 60° | | Also written as 0.562"-36 | 9/16"-36 |
| Colt Python (old), Colt E & I | M14.31 | 0.794 mm | 60° | | Also written as 0.5634"-32 | 9/16"-32 |
| Destroyer 1921 carbine (Spanish) | M15.88 | 0.977 mm | 60° | 15.88 mm | 21.59 mm diameter at the shoulder | 5/8"-26 |
| Ruger GP-100 | M15.88 | 1.058 mm | 60° | | | 5/8"-24 |
| Remington Rolling Block No. 4 Rem. Action (solid frame model)$^{:33}$ | M16.64 | 1.588 mm | 90° | 16.89 mm | Also written as 0.655"-16. | 21/32"-16 |
| Mathieu | Tr16.76 | 2.54 mm | 29° | 16.76 mm | Trapezoidal threads. Also written as 0.660"-20 | 85/128"-20 |
| Ruger Blackhawk | M16.97 | 1.058 mm | 60° | | Also written as 0.668"-24 | 43/64"-24 |
| Smith & Wesson N Frame | M17.02 | 0.706 mm | 60° | | Also written as 0.670"-36 | 43/64"-36 |
| Remington Rolling Block No. 4 Rem. Action (takedown model)$^{:33}$ | ⌀17.15 | (no threads) | N/A | 17.02 mm* | Also written as 0.675". *Of which a length of 5.56 mm of the shank has its diameter reduced to 15.62 mm. | 27/40" |
| Ruger Single Six series | M17.26 | 1.058 mm | 60° | | | 87/128"-24 |
| Colt Single Action Army Revolver (third gen) | M17.35 | 1.058 mm | 60° | 17.75 mm | Also written as 0.683"-24. Only 14.43 mm of the shank is threaded. | 87/128"-24 |
| Colt Single Action Army Revolver (first and second gen) | M17.65 | 1.270 mm | 60° | 17.75 mm | Also written as 0.695"-20. Only 14.73 mm of the shank is threaded. | 89/128"-20 |
| M1917 revolver | M17.65 | 1.270 mm | 60° | | Also written as 0.695"-20 | 89/128"-20 |
| Ruger Redhawk | M19.05 | 1.270 mm | 60° | | | 3/4"-20 |
| Falling Block Works (FBW) Model K$^{:68}$ | M19.05 | 1.588 mm | 60° | 25.15 mm | | 3/4"-16 |
| Stiller SPF 2500X | M19.05 | 1.588 mm | 60° | | | 3/4"-16 |
| BSA Martini Cadet$^{:53}$ | M19.05 | 1.814 mm | 55° | 16.74 mm | Maximum 25.40 mm shoulder | 3/4"-14 |
| Marlin 336, 1895 (.45-70) | Sq19.69 | 2.117 mm | 90° | 21.59 mm | Square threads | 0.775"-12 |
| Marlin 1895 (.450) | M19.69 | 2.117 mm | 60° | 21.59 mm | | 0.775"-12 |
| Ruger Mini-14 | M20.64 | 1.270 mm | 60° | | | 13/16"-20 |
| Colt AR-15 | M20.64 | 1.588 mm | 60° | | The barrel nut thread is M31.75 x 1.411 mm (1-1/4"-18) | 13/16"-16 |
| HK416, HK MR223, HK MR556 | M21 | 1.5 mm | 60° | | The barrel nut thread is M32 x 1.5 mm (1.26"-16.93) | 0.827"-16.93 |
| Remington Rolling Block No. 2 Rem. Action$^{:33}$ | Sq21.59 | 2.117 mm | 90° | 30.48 mm* | Square threads. Also written as 0.850"-12. *Of which a length of 10.16 mm of the shank has its diameter reduced to 20.45 mm | 17/20"-12 |
| Remington Rolling Block No. 1-1/2 Rem., Sporting Action$^{:33}$ | Sq21.59 | 2.117 mm | 90° | 36.65 mm* | Square threads. Also written as 0.850"-12. *Of which a length of 12.70 mm of the shank has its diameter reduced to 20.32 mm | 17/20"-12 |
| Remington 1867 Navy pistol | Sq21.59 | 2.117 mm | 90° | | Square threads. Also written as 0.850"-12. | 17/20"-12 |
| Kimber M/84 | M21.43 | 1.27 mm | 60° | | | 27/32"-20 |
| Sako L46/L-46 | M21.72 | 1.588 mm | 60° | 21.46 mm | Also written as 0.855"-16. | 55/64"-16 |
| Howa 1500 Mini Action | M22 | 1.5 mm | 60° | | | |
| Zastava M85 «Mini Mauser» | M22 | 1.5 mm | 60° | | | 0.866"-16.93 |
| Sako L461 | M22 | 1.6 mm | 60° | 19.40 mm | | 0.864"-15.87 |
| Mossberg MVP .223 | M22.23 | 0.907 mm | 60° | | Also written as 0.875"-28. | 7/8"-28 |
| Weatherby Mark V Varmint, Weatherby Mark V Varmintmaster | M22.23 | 1.411 mm | 60° | 16.99 mm | | 7/8"-18 |
| Cooper Model 22 | M22.23 | 1.588 mm | 60° | 16.26 mm | | 7/8"-16 |
| Savage Model 1920 | Sq22.86 | 2.117 mm | 90° | | Square threads. Also written as 0.900"-12. | 29/32"-12 |
| Browning BPCR, 1885 | M23.75 | 1.270 mm | 60° | 23.37 mm | Also written as 0.935"-20. | 15/16"-20 |
| Winchester 1885$^{:20}$ | M23.75 | 1.588 mm | 60° | 23.37 mm | | 15/16"-16 |
| Browning A-Bolt (early), Browning BBR, Remington 7600 | M23.81 | 1.270 mm | 60° | | | 15/16"-20 |
| TAP-174, TAP-375 | M24 | 1.0 mm | 60° | 19.75±0.05 mm | 27.50 mm shoulder | 0.945"-25.4 |
| Sako AI/A1 (PPC, Vixen) | M24 | 1.5 mm | 60° | | | 0.945"-16.93 |
| Jalonen JJ-91 | M24 | 1.5 mm | 60° | | | 0.945"-16.93 |
| Keppeler | M24 | 1.5 mm | 60° | 18 mm | | 0.945"-16.93 |
| Loppo 1, Loppo 2 | M24 | 1.5 mm | 60° | 20 mm | | 0.945"-16.93 |
| Remington Rolling Block No. 1 Rem., Blackpowder Action$^{:33}$ | Sq24.77 | 2.117 mm | 90° | 36.02 mm* | Square threads. Also written as 0.975"-12. *Of which a length of 10.62 mm of the shank has its diameter reduced to 23.37 mm | 39/40"-12 |
| Mosin-Nagant M91/30 | M24.64, M24.77 M24.89 | 1.588 mm, 1.588 mm, 1.814 mm | 55/60° | 23.88 mm | 30.02 mm shoulder. Thread angle varies. | 0.970"-16, 0.975"-16, 0.980"-14 |
| MAS M-1936 | M24.89 | 1.588 mm | 60° | 21.46 mm | Also written as 0.980"-16. | 63/64"-16 |
| Husqvarna 1640, | M24.89 | 2.117 mm | 55° | 18.16 mm | 27.94 mm shoulder. Also written as 0.979"-12. | 63/64"-12 |
| Mauser small ring: Mauser G33/40, Model 93, 94, 95 Swedish m/1896 and m/1938 | M25 | 2.117 mm | 55° | 18.16 mm / 16.38 mm / 15.88 mm / 16.2+0.2 mm | 24.89 mm major diameter. 27.94 mm shoulder | 0.980"-12, 0.993"-12 |
| Krag–Jørgensen, American model (US Krag-Jørgensen) | Tr24.89 | 2.54 mm | 29° | 19.23 mm | Also written as 0.979"-10. Trapezoidal threads, 24.89 mm shoulder | 63/64"-10 |
| CZ 527, BRNO FOX | M25 | 1.25 mm | 60° | | Also written as 0.984"-20.32. | 1.024"-20.32 |
| Krico 500, 700, M600, M700 | M25 | 1.25 mm | 60° | 19.85-0.1 mm | 28.00-0.05 mm shoulder | 0.984"-20.32 |
| Krico M-600, Tradewind 600 | M25 | 1.270 mm | 60° | 20.32 mm | 30.35 mm shoulder | 0.985"-20 |
| Lebel Berthier 8 mm | M25 | 1.411 mm | 55°/60° | 25.53 mm | 29.21 mm shoulder | 0.985"-18 |
| Varberger 717, 757, 777, Kongsberg Lakelander 389, Kongsberg 393 | M25 | 1.5 mm | 60° | 19.75±0.05 mm | 27.50 mm shoulder | 0.984"-16.93 |
| Heym SR 21, SR 30 | M25 | 1.5 mm | 60° | 29.98 mm | 29.25 mm shoulder, 5.90 mm loose recoil lug | 0.984"-16.93 |
| Nikko Model 7000, Golden Eagle Model 7000 | M25 | 1.5 mm | 60° | | | 1"-16.03 |
| FR F1 | M25 | 1.5 mm | 60° | 22 mm | | |
| Sako L57 / L-57 | M25 | 1.5 mm, 1.588 mm | 60° | 21.46 mm | | 0.984"-16.93, 0.984"-16 |
| Sako L-579, L579 Forester, L61 (early) | M25 | 1.588 mm | 60° | 22.10 mm | | 1"-16 |
| Mauser 8 mm (Siamese) | M25 | 1.814 mm | 55° | 13.08 mm | 27.94 mm shoulder | 0.990"-14 |
| Husqvarna 1600, 1900, 2000, 8000, Carl Gustaf 1900, Carl Gustaf 2000 | M25 | 2.117 mm | 55° | 19.56 mm | 27.94 mm shoulder | 0.984"-12 |
| Mauser 89 (Belgian) | M25 | 2.117 mm | 55° | 19.3 mm | 28.32 mm shoulder | 0.985"-12 |
| Mauser 88 (German) | M25 | 2.117 mm | 55° | 18.29 mm | | 0.986"-12 |
| Mauser Brevex Magnum | M25 | 2.117 mm | 55° | 19.56 mm | | 0.988"-12 |
| Mauser 91 (Argentine) | M25 | 2.117 mm | 55° | 21.46 mm | 33.66 mm shoulder | 0.986"-12 |
| Mauser 71/84 | M25 | 2.117 mm | 55° | 21.59 mm | 26.10 mm shoulder | 0.987"-12 |
| Farquharson rifle (Gibbs, Jeffery, and others) | M25.07 | 1.814 mm | 55°/60° | 22.23 mm | Also written as 0.987"-14. Thread angle varies with production year and manufacturer | 1"-14 |
| Husqvarna RB shotgun, RB M67 | M25.10 | 2.117 mm | 55°/60° | 16 mm | | 0.988"-12 |
| Kongsberg M60 jakt, M83, M83S, M83SK | M25.23 | 2.117 mm | 55° | 16.2+0.2 mm | Also written as 0.993"-12. Major diameter 25.23-0.2 mm. | 1"-12 |
| Krag–Jørgensen, Norwegian model | Tr25.30 LH, Sq26.67 LH | 2.117 mm | 90°/29° | 19.5+0.3 mm | 29+0.1 mm shoulder. Left hand threads. *Trapezoidal threads on Steyr manufactured actions, also written as 0.996"-12 LH. *Square threads on Kongsberg manufactured actions, also written as 25.3-0.1 mm. | 1"-12 LH, 1-1/16"-12 LH |
| Browning A-Bolt (late) | M25.40 | 0.794 mm | 60° | | | 1"-32 |
| Mossberg MVP .308, Mossberg 100ATR, Mossberg ATR Night Train, Mossberg 4x4 | M25.40 | 1.270 mm | 60° | | | 1"-20 |
| Remington 788 | M25.40 | 1.270 mm | 60° | 38.1 mm / 39.6 mm | | 1"-20 |
| Ruger No. 1, M77, M77 MkII | M25.40 | 1.588 mm | 60° | 17.53 mm | 35.56 mm shoulder | 1"-16 |
| Colt Light Rifle | M25.40 | 1.588 mm | 60° | | | 1-16 |
| FN FAL | M25.40 | 1.588 mm | 60° | | | 1"-16 |
| Ruger American | M25.40 | 1.588 mm | 60° | 26.8 mm | | 1"-16 |
| Ruger American Magnum | M25.40 | 1.588 mm | 60° | 30.5 mm | | 1"-16 |
| Ruger Precision Rifle (RPR) | M25.40 | 1.588 mm | 60° | | Timing via barrel nut M31.75x1.411 mm (1-1/4"-18 TPI). | 1"-16 |
| Winchester Model 70 (post 64) | M25.40 | 1.588 mm | 60° | 17.78 mm | | 1"-16 |
| Winchester 54/70 (pre 64) | M25.40 | 1.588 mm | 60° | 18.8 mm | 29.08 mm shoulder | 1"-16 |
| Winchester 54/70 (.22 Hornet) | M25.40 | 1.588 mm | 60° | 21.21 mm | 28.96 mm shoulder | 1"-16 |
| Tikka M55, M595, M695 | M25.40 | 1.588 mm | 60° | | | 1"-16 |
| Tikka T3, T3X | M25.40 | 1.588 mm | 60° | 22.10 mm | | 1"-16 |
| Sako L-61 (1. Mod.), Sako L61R Finnbear (early) | M25.40 | 1.588 mm | 60° | | | 1"-16 |
| Sako 75 | M25.40 | 1.588 mm | 60° | | | 1"-16 |
| Sako 85 | M25.40 | 1.588 mm | 60° | | | 1"-16 |
| SIG Sauer CROSS | | | 60° | | | 1"-16 |
| Lee-Enfield (SMLE) | M25.40 | 1.814 mm | 55°/60° | 17.46 mm | 25.32 mm major diameter. Most have a 60 grader thread angle, but some have 55°. A length of 2.54 mm of the shank at the chamber side in unthreaded with a diameter of 22.86 mm diameter. | 1"-14 |
| Homer Koon Omega III | M25.40 | 1.814 mm | 60° | | | 1"-14 |
| Champlin (1968, 1971) | M25.40 | 1.814 mm | 60° | 15.24 mm | | 1"-14 |
| Martini-Henry, Martini-Enfield,$^{:63}$ Metford | M25.40 | 1.814 mm | 55°/60° | 17.78 mm | Thread angle depends on production date | 1"-14 |
| Falling Block Works (FBW) Model S$^{:69}$ | M25.40 | 1.814 mm | 60° | 37.97 mm | | 1"-14 |
| Falling Block Works (FBW) Model H, J$^{:71}$ | M25.40 | 1.814 mm | 60° | 25.15 mm | | 1"-14 |
| Ranger Arms Texas Magnum | M25.40 | 1.814 mm | 60° | 25.15 mm | 29.21 mm shoulder | 1"-14 |
| Navy Arms Pedersoli Remington Rolling block$^{:123}$ | M25.40 | 1.814 mm | 60° | 38.86 mm* | 30.5 mm shoulder. *The final part of the shank has its diameter reduced to 22.86 mm. | 1"-14 |
| M1 Garand, M14, M1A | Tr25.40 | 2.540 mm | 29° | | ACME trapezoidal threads. 24.66 mm-0.13 mm major diameter, 23.19 mm- 0.13 mm minor diameter, 1.32 mm-0.08 mm average thread width. Internal radius of 0.25 mm, external radius of 0.13 mm. | 1"-10 (0.968"-10) |
| Sauer 202 Magnum | ⌀__mm | N/A | N/A | | Clamp coupling | |
| DPMS G2, Remington R10 | | | 60° | | The barrel nut threads are M33.34 x 1.411 mm (1-5/16"-18) | |
| Armalite AR-10, Eagle Arms AR-10, Noveske Rifleworks N6 | M25.40 | 1.588 mm | 60° | | The barrel nut threads are M36.51 x 1.411 mm (1-7⁄16-18, tolerance class 3A). | 1"-16 |
| DPMS LR-308 S&W M&P 10, Bushmaster ORC, Remington R25, POF P-308*, (and most other AR308 / 308AR) | M25.40 | 1.588 mm | 60° | | The barrel nut threads are M36.51 x 1.588 mm (1-7/16"-16, tolerance class 2A). *Tolerance class 2B | 1"-16 |
| Ithaca / Tikka LSA-55 | M25.91 | 1.588 mm | 60° | | | 1.020"-16 |
| HK417, MR308, MR762 | | 1.5 mm | 60° | | Barrel nut | ?-16.93 |
| Sauer 80, 90, 92, Carl Gustaf 3000, Colt Sauer | M26 | 1.5 mm | 60° | | | 1.024"-16.93 |
| Howa 1500, S&W 1500, Mossberg 1500, Weatherby Vanguard | M26 | 1.5 mm | 60° | 17.91 mm | 3.8 mm depth countersink for the bolt head with a 17.9 mm diameter | 1.023"-16.93 |
| Arisaka T99 | M26 | 1.5 mm | 60° | 17.78 mm | 31.93 mm shoulder | 1.024"-16.93 |
| Remington 799 | M26 | 1.5 mm | 60° | | | 1.020"-16.93 |
| Arisaka T38, T44 | M26 | 1.75 mm | 60° | 18.29 mm | 28.58 mm shoulder | 1.024"-14.51 |
| Schultz & Larsen Model S4J, Model 68DL | M26 | 1.8 mm | 60° | | | 1.024"-14.11 |
| Steyr-Mannlicher M1895 | M26 | 1.814 mm | 60° | 17.60 mm | | 1.023"-14 |
| Springfield M1903 A3/ A4 | Sq26.42 | 2.540 mm | 29° | 18.64 mm | Square threads, 29.08 mm shoulder, 26.42 mm major diameter, 25.15 mm minor diameter, 1.30 mm + 0.05 mm average thread width. Also written as 1.040"-10. | 1-3/64"-10 |
| The Newton Rifle, Buffalo Newton 1924 | Sq26.42 | 2.540 mm | 90° | | Square threads | 1.040"-10 |
| Sako L61/L-61 (late), Sako L61R Finnbear (late) | M26.59 | 1.588 mm | 60° | 22.10 mm | Also written as 1.046"-16 | 1-3/64"-16 |
| Remington 700, 721, 722, 725, XP-100, Defiant | M26.67 | 1.588 mm | 60° | 22.48 mm | 30.35 mm shoulder. Also written as 1.050"-16. | 1-1/16-16 |
| Remington Rolling Block No. 1 M/1902, 7 mm Action$^{:33}$ | Sq26.80 | 2.117 mm | 90° | 36.32 mm* | Square threads. Also written as 1.055"-12. *Of which a length of 10.92 mm of the shank has its diameter reduced to 25.40 mm | 1-7/128"-12 |
| Remington 783 | M26.80 | 0.907 mm | 60° | | Also written as 1.055"-28 | 1-1/16"-28 |
| Savage Small shank (M110, M-110, M110 C, 112) | M26.80 | 1.270 mm | 60° | 42.06 mm | Also written as 1.055"-20 | 1-1/16"-20 |
| Nucleus, Mausingfield | M26.80 | 1.270 mm | 60° | | Also written as 1.055"-20 | 1-1/16"-20 |
| BAT TR (serienr. over 100) | M26.92 | 1.411 mm | 60° | 23.37 mm | | 1-1/16"-18 |
| BAT Bumblebee, Vampire, Igniter | M26.92 | 1.411 mm | 60° | 19.61 mm | | 1-1/16"-18 |
| Krag–Jørgensen, Danish model | M26.92 | 2.117 mm | 55°/60° | 27.43 mm | Conical threads | 1-1/16"-12 |
| Mannlicher–Schönauer (Greek) | M26.92 | 2.117 mm | 60° | 18.47 mm | Also written as 1.059"-12. | 1-1/16"-12 |
| Kongsberg M48 rescue gun | M26.92 | 2.117 mm | 55° | 18.03 mm | Also written as 1.059"-12. 29.85 mm shoulder diameter. | 1-1/16"-12 |
| Mauser FÉG 35M, G98/40 | M26.92 | 2.117 mm | 55° | 18.03 mm | 29.85 mm shoulder | 1-1/16"-18 |
| Defiance Deviant | M26.97 | 1.588 mm | 60° | 24.26 mm | 3.8 mm depth countersink for the bolt head with a 17.9 mm diameter | 1-1/16"-16 |
| HS Precision 2000 Short Action | M26.97 | 1.588 mm | 60° | | | 1-1/16"-16 |
| Surgeon 591 Short Action | M26.97 | 1.588 mm | 60° | 24.13 mm | 3.8 mm depth countersink for the bolt head with a 17.9 mm diameter | 1-1/16"-16 |
| Thompson/Center Icon | M26.97 | 1.588 mm | 60° | | | 1-1/16"-16 |
| Ultimatum Deadline Short Action | M26.99 | 1.270 mm | 60° | | | 1-1/16"-20 |
| Kelbly Atlas | M26.99 | 1.411 mm | 60° | 17.58 mm | Also written as 1.061"-18 | 1-1/16"-18 |
| Kelbly Long Atlas | M26.99 | 1.411 mm | 60° | 14.15 mm | | 1-1/16"-18 |
| BAT S, SV, B, DS, 3L, 3LL | M26.99 | 1.411 mm | 60° | 26.7 mm | | 1-1/16"-18 |
| BAT SB, MB | M26.99 | 1.411 mm | 60° | 26.7 mm | The shoulder must have a radius | 1-1/16"-18 |
| Kelbly Atlas Short Action, Atlas Long Action | M26.99 | 1.411 mm | 60° | 14.15 mm | | 1-1/16"-18 |
| BAT VR, BTA, TR (TR with serial number below 100) | M26.99 | 1.411 mm | 60° | 17.68 mm / 19.61 mm | | 1-1/16"-18 |
| Stolle Panda Short Action | M26.99 | 1.411 mm | 60° | 28.32 mm | 30 degree countersink for the bolt head | 1-1/16"-18 |
| Stolle Panda Long Action | M26.99 | 1.411 mm | 60° | 24.89 mm | Straight bolt head | 1-1/16"-18 |
| Curtis Vector | M26.99 | 1.588 mm | 60° | | | 1-1/16"-16 |
| Weatherby Mark V, Mark V Magnum | M26.99 | 1.588 mm | 60° | 17.53 mm | | 1-1/16"-16 |
| Weatherby Mark V Magnum | M26.99 | 1.588 mm | 60° | 17.78 mm | 29.21 mm shoulder | 1-1/16"-16 |
| Stiller Predator | M26.99 | 1.588 mm | 60° | 25.15 mm | 3.8 mm depth countersink for the bolt head with a 17.9 mm diameter | 1-1/16"-16 |
| Sauer 200, 202, SIG Sauer 200 STR, 205, 3000, Carl Gustaf CG 4000 | ⌀27 mm | N/A | N/A | 36.5 mm | Clamp coupling. The clamping section is 36.5 mm long. The clamping portion of the 202 is somewhat shorter, such that 200 STR barrels can be used in the 202 without modifications (but not necessarily the other way around). | 1.063" |
| Sauer 303 | ⌀__mm | N/A | N/A | | Clamp coupling. | |
| Sauer 404 | ⌀__mm | N/A | N/A | | Clamp coupling. | |
| Jalonen JJ-92A | M27 | 1.5 mm | 60° | | | 1.062"-16.93 |
| Sardec | M27 | 1.5 mm | 60° | 25 mm | | 1.062"-16.93 |
| Sako TRG22, TRG-S, M995, Sako S20 | M27 | 1.5 mm | 60° | | | 1.062"-16.93 |
| Carcano M91 | M27 | 1.75 mm | 60° | 27.05 mm | 28.83 mm shoulder. Also written as 0.968"-14. | 1.062"-14.51 |
| Accuracy International Short action AI (AT, AX308, AE, AW) | M27 | 2.0 mm | 60° | | Indexed via a set screw | 1.063"-12.7 |
| Steyr-Mannlicher M1895 | M27, M26.99 | 2 mm, 2.117 mm | 60° | 24.38 mm | | 1.063-12.7, 1-1/16"-12 |
| Kongsberg M52 (jakt, redningsgevær), M55 jakt, M58 skarpskytter, M59 skarpskytter, M62 jakt, M63 selfangstgevær, M64 treningsgevær, M67 skarpskytter, M80 skarpskytter, M85E | M28 | 2.117 mm | 55° | 16.2+0.2 mm | 27.9 mm major diameter. Also written as 1.098"-12. | 1.098"-12 |
| Husqvarna 640 | M28 | 2.117 mm | 55° | 16.2+0.2 mm | | 1.098"-12 |
| Norinco Model 1887 | M28 | 0.977 mm | 60° | | Clone of Winchester Model 1887 | 1.100"-26 |
| Savage Bolt Action Shotgun | M28 | 1.270 mm | 60° | | | 1.100"-20 |
| Heym SR 10, SR 20, Mauser 2000, 3000 | M28 | 2.117 mm | 60° | | | 1.100"-12 |
| CZ BBK-02 | M28 | 2.117 mm | 60° | | | 1.100"-12 |
| Fabrique Nationale 222 Benchrest | M28 | 2.117 mm | 55°/60° | 15.9 mm | Built on Mauser 98 actions | 1.100"-12 |
| Zastava M70 / M98 | M28 | 2.117 mm | 55° | | | 1.100"-12 |
| Voere Shikar, K-14 | M28 | 2.117 mm | 60° | | | 1.100"-12 |
| Mauser large ring: Mauser K98k, M98, Mauser Model 24 (Yugoslavian) Interarms Mark X | M28 | 2.117 mm | 55° / 60° | 16.2+0.2 mm / 15.88 mm | Major diameter 27.90-0.10 mm | 1.100"-12 |
| CZ 550, 557, 602 | M28 | 2.0 mm | 60° | | | 1.102"-12.7 |
| Kongsberg Rolling Block (RB) M/1867 | M28 | | 55° | | | |
| Kongsberg RB shotgun | Tr | | 29° | | Trapezoidal threads | |
| Jarmann M/1884 | | | 55°/60° | | | |
| Savage Large Shank | M28.58 | 1.270 mm | 60° | | Also written as 1.120"-20 | 1-1/8"-20 |
| Savage 110 (short magnum), Ultimatum Deadline Long Action | M28.58 | 1.270 mm | 60° | | | 1-1/8"-20 |
| Tubb 2000, Tubb ATR | M28.58 | 1.411 mm | 60° | | Barrel coupler is 1-3/4"-18 | 1-1/8"-18 |
| Armalite AR-30 | M28.58 | 1.411 mm | 60° | | UNEF, tolerance class 3A | 1-1/8"-18 |
| BAT M | M28.58 | 1.588 mm | 60° | 26.67 mm | | 1-1/8"-16 |
| BAT HR, BTLA | M28.58 | 1.588 mm | 60° | 17.30 mm / 19.25 mm | | 1-1/8"-16 |
| Herters (BSA) U-9 | M28.32 | 2.117 mm | 55° | 23.37 mm | 31.37 mm shoulder. Also written as 1.115"-12. | 1-1/8"-12 |
| Falling Block Works (FBW) Model L Express$^{:72}$ | M28.58 | 2.117 mm | 60° | 25.15 mm | | 1-1/8"-12 |
| Enfield P-14 | Tr28.58 | 2.54 mm | 29° | 18.29 mm | Trapezoidal threads, 33.66 mm shoulder | 1-1/8"-10 |
| Enfield 1917 | Tr28.58 | 2.54 mm | 29° | 20.32 mm | Trapezoidal threads, 33.66 mm shoulder | 1-1/8"-10 |
| Enfield P-14, M1917 | Sq28.58 | 2.54 mm | 90° | | Square threads | 1-1/8"-10 |
| Remington 30, 30S, 720 | M28.58 | 2.54 mm | 60° | 18.29 mm | 33.66 mm shoulder | 1-1/8"-10 |
| Accuracy International Long action magnum AI (AXMC, AX338) | M30 | 2.0 mm | 60° | | Indexing via set screw | 1.181"-12.7 |
| BAT CT | M30.16 | 1.588 mm | 60° | 26.42 mm | | 1-3/16"-16 |
| BAT L | M31.75 | 1.588 mm | 60° | 44.2 mm | | 1-1/4"-16 |
| BAT EX with CHEY-TAC breechface | M38.10 | 1.588 mm | 60° | 37.34 mm | | 1-1/2"-16 |
| BAT EX with 50 BMG breechface | M38.10 | 1.588 mm | 60° | 34.80 mm | | 1-1/2"-16 |

### Alternative methods

Several alternative mounting methods to using action threads exist.

#### Barrel press fit

    Pressing the barrel into the receiver to achieve a press fit is an alternative to using action threads which has been used on firearms such as Anschütz Fortner, Anschütz Model 54, AKM and Sauer 101.

#### Barrel nut

    Attaching the barrel to the receiver using a barrel nut and a barrel with a shoulder is an alternative to action threads, which has been used in firearms such as the Sten gun and AR-15.

#### Hand tools

    Quick barrel change systems is an increasingly popular alternative, as seen in for example SIG Sauer 200 STR, Roessler Titan or Blaser R8. These methods typically only require simple hand tools (like a hex key) or no tools at all. This can be a great advantage to competition shooters who regularly wear out barrels, or for hunters who want a modular rifle that can shoot several calibers. In these designs, the bolt locks directly into the barrel, and the manufacturer often guarantees that the barrel is headspaced correctly from the factory.
* A quick change barrel system using threads, intended to be assembled and disassembled without tools.

## Muzzle threads

Muzzle threads is one method of fitting accessories such as flash hiders, suppressors or muzzle brakes (compensators). The applicable thread is limited to a certain degree by the bullet caliber and barrel diameter. Right-hand threads (RH) are most common, but left-hand threads (LH) are sometimes used instead. Unless otherwise stated, right-hand threads are usually assumed.
In Europe it has become common to use 1 mm muzzle thread pitches. M14x1 is a common thread type on European hunting barrels, while M18x1 is common on competition bull barrels. A larger barrel thread diameter can improve the precision of the barrel. As of 2021, various Unified threads are still the de facto standard on most American firearms, such as 1/2"-28 (M12.7x0.907) on 5.6 mm (.223") caliber rifles and 5/8"-24 (M15.88x1.058) on 7.62 mm (.308") calibers.
Some common barrel threads are listed below:
Common muzzle threads :
| Diameter | Pitch | Comment | Inch |
| M12.7 | 0.907 mm | Common on American rifles and pistols chambered for .223 Rem, .22 LR and 9×19mm. | 1/2"-28 |
| M12.7 | 1.270 mm | Common on older European rifles chambered for .22 LR. | 1/2"-20 |
| M13.5 | 1 mm LH | Some European 9×19mm pistols | 69/128"-25.4 LH |
| M14 | 1 mm | Very common on European hunting rifles. Also used on some airsoft guns (although often in the left-hand version). | 71/128"-25.4 |
| M15.88 | 1.058 mm | Very common on American rifles chambered for the 7.62 caliber (for example .300 BLK, 7.62x39 mm, .308 Win) | 5/8"-24 |
| M18 | 1 mm | Common on European rifles with bull barrels. | 45/64"-25.4 |
Less common muzzle threads :
| Diameter | Pitch | Comment | Inch |
| M8 | 0.75 mm | Some .22 LR pistols | 20/64"-33.87 |
| M9.53 | 1.058 mm | Some .22 LR pistols | 3/8-24 |
| M12.7 | 0.706 mm | Some 9 mm rifles | 1/2"-36 |
| M13 | 1 mm | Older Glock 9×19mm, Galil (5.56 and 7.62 mm) | 33/64"-25.4 |
| M13 | 1 mm LH | Steyr AUG | 33/64"-25.4 LH |
| M14 | 1 mm LH | AK-47 and AKM. Also common on airsoft guns. | 71/128"-25.4 LH |
| M14.29 | 1.058 mm | Some .40"/10 mm pistols. Used on some rifles in .223", 6.5 mm, .308", and 9×19mm. | 9/16-24 |
| M14.29 | 1.058 mm LH | FN FAL | 9/16-24 LH |
| M14.68 | 0.907 mm | Some pistols in .45-kaliber. Also written as .578"-28. | 74/128"-28 |
| M15 | 1 mm | Some German rifles. | 38/64"-25.4 |
| M16 | 1 mm | .45 caliber pistols from HK. | 20/32"-25.4 |
| M16 | 1 mm LH | .45 caliber pistols from HK. | 20/32"-25.4 LH |
| M17.46 | 1.058 mm | Some American 7.62 mm bull barrels, as well as some barrels for .450 Bushmaster (11 mm caliber). | 11/16-24 |
| M18 | 1.5 mm | Accuracy International .338 LM. | 45/64"-16.93 |
| M22 | 0.75 mm | Saiga 12 gauge shotgun | 111/128"-33.87 |
| M22.23 | 1.814 mm | Some rifles in 12.7 mm caliber | 7/8"-14 |
| M24 | 1 mm | Accuracy International 12.7 mm, Micro Uzi, Uzi pistol | 121/128"-25.4 |
| M24 | 1.5 mm | AK-74 (5.45x39 mm) | 121/128"-16.93 |
| M25 | 1 mm | Desert Tech 12.7 | 63/64"-25.4 |
| M25.4 | 1.814 mm | Some rifles in 12.7 mm caliber. | 1"-14 |
| M26 | 1.5 mm | Zastava M85 and M92 (7.62x39 mm), Uzi, Mini Uzi. | 1-3/128"-16.93 |

## External threads on muzzle accessories

Some accessories, notably suppressors and concussion reduction devices (CRDs), attach via a muzzle device such as a flash hider, compensator, thread protector or sleeve.
External threads on muzzle accessories :
| Diameter | Pitch | Comment | Inch |
| M19 | 1.588 mm | Oil filters on Ford, Dodge og Jeep | 3/4"-16 |
| M20 | 2.5 mm | Standard metric coarse thread | 101/128"-10.16 |
| M20.6 | 1.588 mm | Flash hiders from Kineti-Tech. Oil filters from Chevy and GM. | 13/16"-16 |
| M20.6 | 1.814 mm | Standard pipe thread (NPT). | 3/4"-14 |
| M22.9 | 1.058 mm | Q Cherry | .900"-24 |
| M24 | 3 mm | Standard metric coarse thread | 121/128"-8.47 |
| M27 | 1.5 mm | Ase Utra Borelock, Klärig Engineering BL2, Uronen Precision | 1-1/16"-25.4 |
| M28.6 | 2.117 mm | Flash hiders from Cyclone, Angel and Demon, some from SilcencerCo, BattleComp | 1-1/8"-12 |
| M30 | 3.5 mm | Standard metric coarse thread | 1-3/16"-7.26 |
| M34.9 | 0.907 mm | Quietbore Quickie | 1-3/8"-28 |
| M34.9 | 1.058 mm | Some suppressor tubes from SilencerCo, Dead Air, Griffin Armament, ODIN Works, Q LLC, Torrent Suppressors, Area 419, Energetic Armament, YHM, SDTA, Super Precision Concepts, Plan B, Enfield Rifle Company, Rex Silentium, JK Armament, Ronin Factory, JMAC Customs, Enduro, ASR, Aklys Defense. | 1-3/8"-24 |
| M36 | 4 mm | Standard metric coarse thread | 1-27/64"-6.35 |
| M36.5 | 1.270 mm | Suppressor tubes from SDTAC, Diversified Machine, Super Precision Concepts. Maglite D Cell. | 1-7/16"-20 |
| M36.5 | 1.058 mm | Some Diversified Machine suppressors | 1-7/16"-24 |
| M38.9 | 1.058 mm | Some Diversified Machine suppressors | 1-17/32"-24 |
| M42 | 4.5 mm | Standard metric coarse thread | 1-21/32"-5.64 |
| M42.5 | 1.058 mm | Some Diversified Machine suppressors | 1-43/64"-24 |