A 'parting shot' often contains strong emotions or criticism.

Emotional Impact

It's typically the final remark that effectively ends a conversation or argument.

Conversation End

It's meant to be memorable and leave a strong impression, often said dramatically.

In a military context, it describes the last action taken before withdrawal.

Unlike the idiomatic version, this actually refers to firing a weapon.

The shot is strategic, meant to hinder the enemy during a retreat.