>>64390889
Much higher recoil than a weapon of its size and caliber should have because it's straight blowback
Much longer than it would have been with a proper locking action
Penetrates CRISAT just like monolithic 9mm +P
50 squirrel cartridges that are statistically less effective than .32 ACP
Transfers less kinetic energy into the target than the shooter (as do all firearms by physical necessity)
The P90 exists because FN saw an opportunity to sell a backwards 10/22 in a plastic airsoft shell chambered for .22 Centerfire Magnum for thousands of dollars, that's it. It got some government sales over the years because of the sci-fi looks, but most of those agencies are now dropping it because it's notoriously ineffective.