The bullets themselves are a big difference compared to the 22 mag. I love the 22 mag and have for years. The Hornaday V-max is unlike anything available for the 22 mag. Then, when you step up to the 27 gr stuff in the 5.7 you really have a different animal. This bullet has no lead. It has an aluminum core and is designed to tumble inside a body, which really increases the internal damage. I may be wrong, but I believe the shooter at the Fort Hood military base a few years ago was using one of these. Several of the victims tried to charge him. None made it to him.
I'm pretty sure this handgun wasn't designed with 100 yard use in mind, although it is effective beyond typical 9mm range. The bullet designed by FN for the specific application in mind was designed to do its damage by tumbling, which is different than a typical HP defensive bullet. The military and some special law enforcement units use it with a bullet designed to penetrate some vests. Definitely not something available in the 22 mag.
Ballistics aren't the only thing at play here. Additionally, the 5.7 case design is definitely more reliable in an automatic firearm than is the 22 mag, as is the difference in primers used in each. In a defensive, or law enforcement, application, definitely not an apples to apples comparison. I know which I'd want.
YMMV,
M7
PS: the AE FMJ loads fro the 5.7 are crap. They could more legitimately be compared to the 22 mag.
