What I am is a Sci-Fi geek and wannabe author. Last night I had an idea for a cool SF-type gun that instead of using different types of ammunition for different targets/effects, used powerful electromagnetic coils to shape a copper slug as it passed through the barrel, like your quarter shrinker. I imagine this dial-a-round system to be able to produce three shapes:

Hollowpoint -- minimum penetration, but maximum tissue damage;

Parabellum -- balance of penetration and damage; and

Penetrator -- a long, thin, perhaps molten, round to punch through armor.

My questions are:

* Could such a system conceivably be built--I mean, would it violate any laws of physics?

* Based on your description of the physics, I can see how a bullet could be squeezed longer and thinner, but could it be stretched out shorter but fatter, or squashed/stretched into a different shape, like from a parabellum into a hollowpoint?

* Could such a coil be made to actually melt the copper slug? A hit from that could be devastating.

* Would passage through such an intense EM field affect the round's velocity? Accuracy?

I'd be thankful if you could help me.

Tony