Not only that, but you can get a 55 gr bullet going 2100 fps in a 5" 9mm, so why would you pay those ridiculous prices for the 5.7 ammo, hmm?
55 gr 9mm? Where do you find that? The lightest I have ever seen was an 80 gr glaser at 1650fps. And they cost $11/pack of 6!
So, show me a 55 gr 9mm at 2100 fps.