Here's an idea taken from a film I love - Equilibrium
Gun Kata. - Gun stunt, -3 refresh
-You may use your guns skill to defend against fist, weapon and gun attacks.
-You take no penalty when reloading as a supplemental action; if you're in a race to see who reloads first, or anything else having to do with your speed or ability to reload, gain a +1 on the roll.
-You may gain a +1 to attacks with Guns whenever personally outnumbered in a gunfight.
It's a mix of Fast Reload, Target rich environment plus the ability to use Guns as a defense skill. The defense skill is a little more powerful than the average stunt as you can defend yourself from guns without cover, but Fast Reload is a slightly weaker stunt and so I think -3 refresh is quite fair.