Does anyone have any experience with this cartridge? I personally have none so far and I doubt I would be interested in buying a firearm that is chambered for it but it is rather interesting.
NATO evaluation
In 2002 and 2003, NATO conducted a series of tests with the intention of standardizing a PDW cartridge as a replacement for the 9×19mm Parabellum. The tests compared the relative merits of the 5.7×28mm cartridge and the HK 4.6×30mm cartridge, which was created by German small arms manufacturer Heckler & Koch as a competitor to the 5.7×28mm. The results of the NATO tests were analyzed by a group formed of experts from Canada, France, the United Kingdom, and the United States, and the group's conclusion was that the 5.7×28mm was "undoubtedly" the more efficient cartridge.
The 5.7×28mm cartridge was designed by FN Herstal specifically for use in the FN P90 personal defense weapon and FN Five-seven pistol. Subsequently, it has been used in a number of other weapons, such as the FN PS90 carbine and the AR-57, an upper receiver for M16 and AR-15 rifles. The ST Kinetics CPW can be configured for the 5.7×28mm cartridge by changing the barrel and magazine groups. Excel Arms has developed four firearms chambered in 5.7×28mm, and MasterPiece Arms offers three different 5.7×28mm firearms.
The 5.7×28mm cartridge weighs 6.0 grams (93 grains)—roughly half as much as a typical 9×19mm Parabellum cartridge—making extra ammunition less burdensome, or allowing more ammunition to be carried for the same weight. Since the 5.7×28mm cartridge also has a relatively small diameter, a relatively high number of cartridges can be contained in a magazine. The cartridge has a loud report and produces considerable muzzle flash (when fired from a pistol), but it has roughly 30 percent less recoil than the 9×19mm cartridge, improving controllability. Due to its high velocity, the 5.7×28mm also exhibits an exceptionally flat trajectory.
[ame]https://www.youtube.com/watch?v=Z24qwPoCqUo[/ame]