EXCLUSIVE

Former "Sons of Guns" star Glenn Fleming loves his guns ... just not when they're turned against him.

The firearm expert ticked off a gun hater last week by posting pro-gun comments on Facebook. A woman fired back, "If I had one of your guns, I'd shoot your ass off ... and it would be just another shooting."

Fleming went to cops, who tell us they've launched an investigation and will confront the woman.