Engineering:155 mm calibre

155 mm (6.1″) is a common, NATO-standard, artillery caliber. It is defined in AOP-29 part 1 with reference to STANAG 4425. It is commonly used in field guns, howitzers, and gun-howitzers.

Land warfare

Since the late 20th century, most NATO armies have adopted 155 mm weapons as an all-purpose standard. They are seen as striking a good compromise between range and destructive power, while using only a single calibre simplifies logistics. This has led to the obsolescence of larger calibre weapons such as the 175 mm (6.9″) and 203 mm (8″), although some militaries retain 105 mm weapons for their light weight and portability. Russian guns and those of former Soviet bloc countries tend to use 152 mm (5.9″) weapons in similar roles.

Naval warfare

Since the end of WWII, 155 mm has not found any use among naval forces despite its ubiquity on land, with most NATO and aligned navies using 76 mm (3″), 100 mm (3.9″), 114 mm (4.5″), or 127 mm (5″) guns on modern warships. At one point the British Ministry of Defence studied "up-gunning" the Royal Navy's 4.5 inch Mark 8 naval guns to give increased firepower and a common calibre between the Royal Navy and the British Army. However, despite superficially appearing to be inferior based on a simple comparison of round diameters, when firing conventional ammunition the smaller 4.5″ naval gun is comparable to the standard 155 mm gun-howitzer of the British Army. The standard shell from a 4.5″ naval gun has the same, if not better, range and carries twice the HE payload of a standard 155 mm round. Only by using rocket-assisted projectiles (RAP) can most 155 mm guns have comparable range to the 4.5″ naval gun and by doing so there is a reduction in the payload. This is because naval guns can be built much more strongly than land-based self-propelled gun-howitzers, and have much longer barrels in relation to calibre (for example the Mark 8 has a barrel length of 55 calibres, while the standard AS-90 self-propelled gun has a barrel length of 39 calibres). This allows naval guns to fire heavier shells in comparison to shell diameter and to use larger propellant charges in relation to shell weight leading to greater projectile velocities. In addition, even without active cooling, the heavier naval gun barrels allow for a superior sustained rate of fire compared to field guns, and this is exploited with an autoloading system with a capacity of several hundred rounds. The 155 mm is superior to the 4.5″ naval gun in relation to cannon-launched guided projectiles (CLGP); because the 155 mm round is fired at a lower velocity it is much easier for their internal electronic guidance systems to survive being fired.

The US Navy's Advanced Gun System also uses a 155 mm calibre, although it is not compatible with NATO-standard 155 mm ammunition. However, since 2016 no ammunition has been developed and therefore the Advanced Gun System is completely unusable.

155 mm guns

• GC-45 (Canada)
• PLZ-45 (China)
• PLZ-05 (China)
• 155 GH 52 APU (Finland)
• CAESAR (France)
• Canon de 155 mm GPF (France)
• Canon de 155 C modèle 1915 St. Chamond (France)
• Canon de 155 C modèle 1917 Schneider (France)
• GCT (France)
• Obusier de 155 mm Modèle 50 (France)
• TRF1 (France)
• PzH2000 (Germany)
• FH70 (Germany / United Kingdom / Italy)
• Dhanush (howitzer)(India)
• DRDO Advanced Towed Artillery Gun System (ATAGS)(India)
• ATMOS 2000 (Israel)
• Soltam M-68 (Israel)
• Soltam M-71 (Israel)
• Palmaria (Italy)
• Type 75 (Japan)
• Type 99 (Japan)
• 2S19M1-155 (Russia)
• FH-88 (Singapore)
• FH-2000 (Singapore)
• SLWH Pegasus (Singapore)
• SSPH Primus (Singapore)
• Nora B-52 (Serbia)
• 155 mm SpGH Zuzana (Slovakia)
• G5/G6 (South Africa)
• KH179 (South Korea)
• K9 Thunder (South Korea)
• Santa Bárbara Sistemas 155/52 (Spain)
• FH77/Archer Artillery System (Sweden)
• Panter howitzer (Turkey)
• T-155 Fırtına (Turkey)
• AS90/AHS Krab (United Kingdom)
• M1/M2 155 mm "Long Tom" (United States)
• M12 (United States)
• M41 (United States)
• M44 (United States)
• M53 (United States)
• M109 (United States)
• M114 (United States)
• M198 (United States)
• M777 (United Kingdom)
• XM1203 (United States – never entered service)
• XM2001 (United States – never entered service)

155 mm naval guns

• 15.5 cm/60 3rd Year Type naval gun (Empire of Japan – non-NATO compatible)
• Advanced Gun System (United States – in service but with no ammunition available; non-NATO compatible)
• Mark 8 gun (United Kingdom – proposed but never produced, NATO compatible)

155 mm shells

• SMArt 155 (Germany) – submunition-carrying anti-tank shell
• Hypervelocity Projecile (HVP) (United States) – experimental hypervelocity projectile
• Long Range Land Attack Projectile (LRLAP) (United States) – cancelled naval round for the Advanced Gun System
• M107 (United States) – general purpose
• M483 (United States) – submunition-carrying shell for dual anti-armour/anti-personnel roles
• M549 (United States) – rocket-assisted shell
• M687 (United States) – chemical weapon shell
• M692/M731 (United States) – anti-personnel land mine scattering shell
• M712 Copperhead (United States) – laser-guided anti-tank shell
• M795 (United States) – general purpose (replacing M107)
• M864 (United States) – submunition-carrying shell
• M982 Excalibur (United States / Sweden) – GPS-guided shell
• W48 (M454 Artillery Fired Atomic Projectile (AFAP) (United States) – nuclear artillery shell with a yield of 72 tonnes
• Bofors 155 Bonus (Sweden / France) – submunition-carrying anti-tank shell TNT
• K310 (South Korea) – BB/DP-ICM
• K307 (South Korea) – BB/HE
• K315 (South Korea) – HE-RAP