I just picked up a Marlin 17V in .17HMR as a farm gun to shoot ground hogs, rabbits,ect. I was just kicking around the idea of how good/bad this little(and it is little)round would do as a defensive round out of a pistol.  There are a couple different companies making pistols chambered in .17HMR, mostly revolvers. If someone made one in a semi-auto pistol w/10round mag. and a 4"-4.5" bbl. so it could be carried for CCW use I wonder just how effective it'd be. That little 17gr. bullet should fragment and do massive damage to lungs/heart or in the case of a head shot the brain would most certainly be turned to mush. Plus you have the fact of almost no ricochet or over penetration. I wonder if this(or something like it)may be the wave of the future in CCW pistols? What do ya'll think?

Bad idea; it has so little penetration that it is not even recommended for coyotes. It might fragment, but there is NO chance that it would penetrate deeply enough to reach major organs. A .22lr would be FAR superior for self defense.

Unless you are defending yourself against a rabid squirrel, of course. [;D]

Edited to add: Also, it is a fairly high-velocity, bottle-necked cartridge; a short barrel would leave it with little of its already miniscule energy.

Yeah, what he said.  Short barrel=big velocity loss on a velocity dependent round.  Kinda like a 8.5" AR in 5.56.  Whats the point.

I think it would be a damned could people eliminator(ie hostage situations) out of an accurate rifle, because it could do the job and not kill hostages/bystanders behind the subject.

Possibly, but you would have to limit yourself to head-shots and close range (probably 50m) just because the bullet loses velocity fast.

I'm thinkin' it wouldn't work to well either, just wanted to see what everyone else thought. Maybe it if had the right bullet it'd go better, come to think of it, didn't FN have a 4.5mm round chambered in something or another?  I know out to 100 yards out of an accurate rifle it'd do ok with a head shot but like has been said, from a pistol you'd loose too much V to make it an effecive round. Doesn't really matter, I got it to shoot ground hogs and squrills(never could spell that damn word.)with anyway. Talk to ya'll later.

Hope you never have to shoot through anything like a window, winshield, door etc... I don't think it would do well.
If the person is right in front of you standing still and you could make a head shot it would most likely do fine.

I suppose you could try to make a round thats similar to the P90 round. But why would you do it? It already exists with platforms to shoot it.  Not to mention it would most likely not be available to civilians.

Imagine sombody shooting a gun at you. Now what is between you and the bad guy's vitals?  that's right, his weapon and his arms. You need a caliber that is big enough to punch through the hands and arms and still reach the vitals.

In fact, in gun fights people often focus on their opponents weapon and and a result hit the weapon or very near it. Every time we do simunitions training our hands get hit a lot.

I once shot a bear with a .025 GH Magnum (that's right, point oh two five caliber) from a .5" derringer and it stopped him in his tracks.  The bullet was a 2 grain JHP.

The secret has already adopted that round for def...oops wrong thread.  Sorry