General Firearm Discussion
When first comparing the 5.7mm vs. 9mm, one might think they're very different.
The 9mm has a heavier bullet, while the 5.7 is more aerodynamic. The 9x19mm looks like a traditional semi-auto handgun round, and the 5.7 appears to be a miniature rifle cartridge.
The 9mm Luger was developed in...