All have almost the same bullet diameter
Thinking, ".223, 5.56, GP90, .22LR—all the same"? Think again. Four cartridges, four uses, and each with its own personality. In short: you shoot one for training, another for the military—and you might even like the third out of habit.
The bullets of .223 Rem / 5.56×45 mm / GP90 have a diameter of 0.224 inches (≈ 5.69 mm) , while the .22 LR just under 0.22 inches (≈ 5.59 mm) .
When engaging in sport or service shooting, one quickly encounters various cartridge designations that can seem confusing at first glance. The calibers .223 Rem , 5.56x45mm NATO , GP 90 , and the small .22lr . Although they sometimes look very similar, there are significant differences in dimensions, pressure, and application.
When engaging in sport or service shooting, one quickly encounters various cartridge designations that can seem confusing at first glance. The calibers .223 Rem , 5.56x45mm NATO , GP 90 , and the small .22lr . Although they sometimes look very similar, there are significant differences in dimensions, pressure, and application.
GP 90 (5.6mm Gw Pat 90)
- Origin: Standard ammunition of the Swiss Army, introduced in 1990 for the Sturmgewehr 90 (SIG SG 550) .
- Technical basis: Ballistically very similar to the 5.56x45mm NATO, but manufactured Swiss specifications
- Bullet: Often with a coated full metal jacket bullet to reduce barrel wear and powder residue.
- Area of use: Military in Switzerland, but also popular with civilian shooting clubs that shoot service rifles.
.223 Remington
- Origin: Civilian caliber, introduced in the USA in the 1960s.
- Pressure & Dimensions: The cartridge is very similar to the military 5.56x45mm NATO, but is loaded with slightly lower gas pressure.
- Area of application: Popular in civilian shooting sports (e.g. AR-15, repeater) and when hunting predators .
- Special feature: Many sporting gun manufacturers offer their rifles in .223 Rem as standard.
5.56x45mm NATO
- Special feature: In weapons designed for 5.56 NATO , you can usually also fire .223 Rem safely – conversely, you should be careful.
- Origin: Military development of the .223 Rem for NATO troops.
- Pressure & Dimensions: can lead overpressure problems when using 5.56 in pure .223 chambers
- Application: Standard cartridge for many NATO rifles (M16, M4, FN SCAR, G36, etc.).
.22 Long Rifle (.22lr)
- Origin: Very old cartridge (in use since the end of the 19th century).
- Pressure & Dimensions: Rimfire ignition (instead of centerfire), very low gas pressures.
- Application: Widely used in sport shooting , training , and recreational shooting . Due to its low recoil and ammunition costs, the .22lr is perfect for beginners.
- Special feature: Not to be confused with the other cartridges (GP90/.223/5.56) – it is significantly smaller and weaker.
Summary
- GP 90: Swiss standard ammunition, technically closely related to 5.56 NATO.
- .223 Rem: Civilian version, slightly lower pressure.
- 5.56 NATO: Military version, higher pressure, not always 1:1 interchangeable with .223.
- .22lr: A completely different caliber, small, inexpensive, ideal for training and leisure.
