I seriously use Dexron vi on most of the heavy working components of my pistols and rifles. Such as on rails and trigger mechanisms. My thought process (from being a transmission tech) is synthetic trans oil takes heat and pressure that no gun will ever experience and doesn't break down easily, it's blended with detergents for cleaning out the dozens of little passages inside the valve body, and it's not hygroscopic like other lubricants... To me its a win situation. The issue... it really smells like complete crap when it gets hot.
My .02 take it or leave it.
When I die better bury me deep, two .45s layin' at my feet,
An M16 across my chest, tell Chesty Puller I did my best