Hoppe's #9 gun oil ? Clear, odorless, mineral oil. All "gun oil" is pretty damned pricy for what it is. I've used straight ATF for 30 years with no complaints. At work we use Mobil vactra oil #2 for lubing the pistols we build.
Wow, Vactra #2? That's some pretty thick and sticky stuff (relative to gun oil), although it's certainly good at staying put and a great lubricant. It's what I use on my mill and lathe machine ways.
