Basil,
This replies to your inquiry re the Winchester Black Talons as personal defense ammunition. I have not used Black Talons, but their reputation certainly is excellent. I would categorize both the Talon and the Hydra-Shok designs as excellent defensive loads.
With this said, I suggest you fire 50 (or 100) rounds from your new Sig to ascertain if either has a proclivity to jam or if either provides noticeably improved accuracy. Obviously, I would opt for the round that always fired! My rationale for remaining with Hydra-Shocks in .380, .45 ACP, .357 magnum, .40 S&W, and .357 Sig is a perfect record in trial firing.
Further, with any handgun -- but particularly with a 9mm -- SHOT PLACEMENT IS CRUCIAL. Accordingly, practice is essential. Keep practicing until you feel confident that you can hit what you're aiming for -- under various conditions and at ranges out to 15 yards.
With respect to "carry through", one must be concerned with the possibility that a round fired in defense -- even if it hits the target -- will pass through that body and harm innocent individuals. Physics mandates that greater mass -- and particularly greater velocity -- will impart enhanced stopping power; but it also provide an increased probability that a round will pass through the target (and, perhaps, through walls, doors, automobile parts, and so forth) and injury an innocent. In addition, the bullet's design is critical to "carry through", with ball/FMJ rounds probably having a greater possibility of passing through the target and then injuring innocents than expanding or frangible rounds (such as the Hydra-Shok). Accordingly, important considerations in your choice of ammunition are its velocity, mass, and bullet design. These elements must be evaluated against your likely defensive environment(s).
An example may help clarify this major point: A police officer who anticipates the possibility of having to fire through automobile bodies might opt for a 153 grain, FMJ, .357 magnum load. This round has unusually high velocity, reasonable mass, and is designed for penetration. On the other hand, that same round might be unduly hazardous -- due to "carry through" -- in an apartment building where interior walls are made entirely of soft pine 2x4s and wallboard.
To summarize, your decisions -- including the choice of ammunition -- when carrying a lethal weapon have obvious and grave ramifications. I urge you to evaluate ALL the germane factors with care.
[This message has been edited by RWK (edited March 14, 2000).]