I remember seeing that the 10mmAuto may be illegal in certain states (California, etc.). Not that they have any ratonale, but what is their justification, does the 10mmAuto penetrate body armor, etc?

Deke.

Illegal for hunting maybe. Several states do not allow any semiauto for hunting. I did see something about California and the 10mm, however, in another thread. Check "handgun hunting".
Peter.

Nope. Never heard of a specific caliber being banned, maybe a type of projectile, but not a caliber.

An indoor range may 'ban' the use of a 10mm if for no other reason than it makes your ears ring - extremely LOUD cartridge.

-Spencer

Meets the big game requirements in Colorado, but would definately hunt smaller Deer and Pronghorns before thinking about anything else. Could have sworn a 10mmAuto semi pistol could not be sold in some places. What about the armor piercing question (see that some perps are starting to wear this stuff.....)?

Deke.

I know Kalif. wants to ban some .50calibers, but I have bought & own 10mms here in this fine socialist state.

A 10mm isn't designed as an AP round, and generally isn't as powerful as a lot of other rounds, like a .44 mag. which is generally fairly common. I'm really not up on the levels of body armor, but I think level 2, or maybe level 3 is rated for a .44 - and that would easily stop a 10mm also.

I'm not sure how whatever armor any given perp. may or may not wear would have any bearing on whether a round was restricted from civilian use.

Possibly if it would go through police armor, it might raise some eyebrows, but even that shouldn't make any difference whatsoever with what any perp. buys. In either case, a decent vest will stop a 10mm.

I own four of them because they are more powerful than a 45ACP with no more kick. Great for bowling pin shoots. Even had one made up on a Ruger Blackhawk frame. My loads have 180gr bullet doing 1150fps 10 ft from the muzzle. If they are illegal anywhere I don't know it. The FBI tried them after their Florida fiasco some years ago but got away from them because "they kick to much". Also heard that S&W quit making the 610 revolver so I'm glad I already have one.