[zentiggr]

Howitzers (retired/surplus military guns, before purpose built varities were designed) are used to clear snow accumulations and prevent catastrophic avalanches.

Charges that would be considered equivalent to land mines are used to implode buildings.

Demolition charge equivalents put out oil fires.

And any projectile or missile ever made can be fired in a purely defensive use, although that's more of a moral boundary than a benign usage per se.