[mikeash]

That's rather stupid. Generally, it is not the bullet that is considered to be the dangerous weapon, but the gun which fires it.

If the lawyer thinks a high-speed potato can't kill somebody, I suggest he go give it a shot (pun intended) and see what happens.

[nwh]

The bullet contains everything you need, not the gun. Lead and propellent, the gun is just a convenient tube and handle.

[jlgreco]

In addition to mikeash's correction, a round does not contain everything that you need. Without a chamber, a bullet is not going anywhere at a particularly dangerous speed. The casing is really not meant to contain the pressure of the burning propellant by itself and without a barrel then the expanding gases from the burning propellant would primarily dump their energy into the environment, not the bullet. In fact, without a chamber and barrel, the casing is actually more dangerous than the bullet, though still would not be deadly. This makes sense when you consider that the casing weights far less than the bullet.

The "tube" is essential, not merely convenient.

[mikeash]

You're thinking of the cartridge. The bullet is just the projectile, and does not include the propellant.

[charonn0]

You're all way over-thinking potatoes.

[mikeash]

I don't think so. Any projectile of decent mass will be deadly when accelerated to high speed. There's nothing that magically exempts potatoes from this just because they're edible. You can absolutely kill someone with a potato gun. The prosecution in question may be wrong for other reasons (e.g. fired safely and not with any intent to harm), but "potatoes can't kill, because otherwise Ireland would be a superpower" is not the way to argue it.

[charonn0]

    "potatoes can't kill, because otherwise Ireland would be a superpower" 
    is not the way to argue it.

I never made such an argument.

[mikeash]

You didn't, but the lawyer referenced in the original comment I replied to said essentially that.