Two of my players came up with an idea to make snap shot and sudden knife reaction cards. I ran with the idea and came up with these rules:

Snap shot Reaction Card
Snaps shot is now a reaction card with the following requirements: This attack may be played when you or an ally within close range is declared the target of a melee attack. This attack resolves before that attack takes place. Black powder weapon equipped, target within close range, no other action cards recharging.

Sudden knife reaction card
Sudden knife is now a reaction card with the following requirements: This attack may be played when an enemy moves to engage you. Not engaged with an enemy, target within close range. The recharge rating of sudden knife is one scene, meaning it recharges at the end of combat.

Wish I could delete this, as my comment/questiont was a core rule thing that had slipped me by carry on meistro!