Is the 5.7 FN a good defensive round and pistol?
 

Does anyone know whether this is a good round to consider for defensive purposes? A friend in New Hamshire called me to ask about it and I am not familiar with this round or gun. Anyone out there give me some insights?

Please post this in the correct forum.

Not really. It's a high velocity, small diameter bullet.

I think the folks at FN would argue with Mark's statement considering it shoots the same diameter bullet as the M 16 and works on the same principal of a light bullet doing serious damage due to its high velocity. If Mark is implying that it is an over kill and has too much penetration for street use making it more dangerous to bystanders then in that sense I would agree. I have one and it shoots great but I carry a 38 in the summer and 45 auto when ever it is cool enough to wear a jacket. The penetration of the FN is unbelievable being able to shoot through common body armor like it wasn't even there. I think it might have a place perhaps with law enforcement who patrol in remote places and do not want to carry a rifle. Also it is a fairly large gun though light in weight even when fully loaded with 21 rounds. It has very little recoil when shooting 27 grain aluminum bullets but is very noisy with a lot of muzzle flash.

Yes sir, that was precisely my point. I have some "limited" experience with the FN FIVE SEVEN. I love shooting it, but I wouldn't use it for personal protection.

IIRC, the FN 5.7 was designed as an armor defeating pistol round for the Brit equivalent of the Secret Service. Because of this, it won't drop energy very well. It should drill neat, clean holes through soft tissue.

Yep, that's exactly why it's not good for SD. You don't want nice clean holes through tissue. What you want is massive meat oblitteration, and total vitals destruction.

Exactly. You are better off slinging hollow points against a vest than you are slinging AP against a soft target.

Speaking of vests, I happen to know the man who wrote this: http://www.justnet.org/Lists/JUSTNET%20Resources/Attachments/758/0101.04RevA.pdf
He conducted all of the testing, and has been consulted on all revisions of the original document, which bears his name.
He also tested Dragonskin, and despite what some people say, it IS a worthless product. The only reason that it meets current specs is that the specs were changed. Bullets still go through it like a hot bullet through a butter vest. If you know someone who is wearing it, please tell them that the real authority on body armor advises them to upgrade immediately.

AP 5.7 ammo is restricted to LE/Military. You would be hard pressed to find a non-expanding bullet on the open market. Most of the ammo that is civi legal is HP or Ballistic tip type.
Over penetration? Doubtful. Extreme velocity with expanding bullets leads to fragmentation. Under penetration is more likely.

The 5.7 pistol takes the light bullet/high velocity argument to the nth degree. It is the polar opposite to the .45 ACP. Is it a viable SD round/gun? IMHO probably. Do I own one? NO.

I have heard of 5.7 KB's. Is there a problem with the gun? I don't know, but I won't be buying one any time soon.