[Stirling]

Tested a little:

An M1A2 started with 4 shots and used them all zfiring 1 hex. Over 1 hex it used just one. It could zfire through 6 hexes of trees

An M2A2 started with 6 shots and used 2 each adjacent zfire. Over 1 hex it used just one. It could zfire through 5 hexes of trees.

I rarely use zfire, so I can't say if this is normal or not.