So this would kinda work like the pompson as in:

+Does not require ammo (replaced with an ammo meter)
+Projectile cannot be deflected
-Has a 33% smaller clip size

BUUUUT (now listen cause here's the catch)

+On hit: causes zap
-50% damage penalty.

Ok so now you may wonder "what in tarnation is zap you snake oil seller ???"

Zap causes players the inability to interact with friendly buldings (teleporters and dispensers) includings theirs (spy's sappers, engie's Wrangler, Eureka Effect and PDAs) and partially nullifies cloak on Spies (electric effect) for 10 seconds

Ps: Of course engies can still repair, refill, upgrade and move their buldings they just can't build new ones or destroy old ones