Xcom Apocalypse had a feature where grenades and explosives lying on the floor could explode when they are hit by fire of explosions.
I think it was I good mechanic and I would love to see it in OXCE.
It is probably best done by using a ruleset tag, for example:
ExplodesIfDestroyed: true
with a default value of "false"
For ammunition with the tag, it would mean that the whole magazine would blow up at once and distribute the projectiles with the shotgun mechanic in random directions.