The FN P90 Ammunition.
In 1987 FN developed the first experimental rounds for the P90 sub-machinegun.
These first cartridges were made from necked down .30 M1 cases. Several experiments were conducted with different types and loadings and cases, but finally FN came up with the SS90 ball round.
The SS90 has a 5.7x28mm case. The shape of the projectile is pointed and very sharp. (See image)
The main objectives of the SS90 ammunition were:
Based on these ballistic values, the SS90 round is positioned between the .223 and 9mmx19 NATO round.
Besides the SS90 ball round, other variations were also produced, like a tracer (L91), a dummy cartridges, etc...
In the early 90s the bullet design was slightly changed to decrease the overall length of the SS90. The round was to long to use in the handgun (Five-SeveN).
The second generation ammunition for the P90 weapon system was also produced in a wide range of different loadings.
These and other variations can be found in the image gallery.
The ballistics of the SS190 is more or less the same as the SS90 round.