You can get ammo for the 5.7 up to 3300 fps. This allows for cavitation on part with almost any gun you can name, in a light bullet with almost no recoil. Full auto or not makes little difference; the round is what makes these Guns effective. Legacy rounds simply cannot hold a candle to them.
I have noticed A LOT of bad information on the interwebs about this round.
For example, many have assumed hollow points indicate an expanding round. With the 5.7, this is incorrect. Hollow points in 5.7 rounds are there to initiate the “tumble” of the round after an initial 2-3 inches of penetration. The practical effect is the round does not dump all it’s energy breaching the initial barrier as with “legacy” rounds. Rather, the shape of the bullet expends relatively little energy on initial penetration, then really dumps it as the 7/8 length bullet begins to tumble at the aforementioned depth.
Doubtless, without the hollow point you would see the failure to tumble that has long plagued the 5.56; with it, the round seems to perform brilliantly.