I never had the slightest urge to buy one of the 5.7X28 handguns or carbines.
I don't care how fast that 31 grains is going, it is not going to be as effective as a heavier, larger caliber bullet.
If getting multiple hits is all that important, buy a freaking air soft gun. A fellow should be working on putting one, maybe two effective bullets on target, instead of spray and pray.

Sam......