Tyler Wenrich -- a Virginia 911 operator and emergency medical tech -- got hit with a hefty $9,000 fine, and has been sentenced to 3 weeks in jail -- but seeing as he's already spent that time in prison, the court's calling it even-steven and recognizing it as time served.

Wenrich initially faced up to 12 years behind bars -- the minimum term for smuggling ammo into the country -- after his guilty plea on two counts of ammo possession for two 9mm rounds on May 21.

However, Justice Davidson Baptiste cited "exceptional circumstances" in his case ... adding in a statement "enforcing the mandatory minimum would have been arbitrary and disproportionate and would not serve the public interest."

Wenrich said a weight has been lifted off both his and his wife's shoulders -- especially since his case was a huge emotional rollercoaster ... seeing how he had no idea which way the pendulum would swing.

Wenrich's now itching to head back to the States and reunite with his wife and 18-month-old son.

He previously said he simply forgot he had the ammo with him while cruising to Turks and Caicos for a bachelor bash -- so yeah, he'll be double-checking his luggage from here on out.

Important to note ... T&C doesn't manufacture firearms or ammo, but they've still been finding their way in. Just days before Wenrich's case, Bryan Hagerich, a father of two, dodged a bullet with a suspended 52-week sentence and a $6,700 fine for having hunting ammo in his own checked luggage.