Ballistol.

My grandfather used 3 in 1 his whole life, but then he was downright anal about oiling his guns on a regular basis.  

I personally use Slip 2000.  I like the way after a few applications it almost bonds with the metal without becoming tacky.  This helps in lubrication, firing more rounds before having to oil, and in corrosion protection.  

I'm not going to ride you guys on using products not designed for guns.  I could go on and on about dissolved oxygen levels, temperature limit designs, and moisture content but then the truth to the matter is what its all about is how much attention to give your guns.  That's going to vary individual to individual and within the individual gun to gun.  

What you have decide is how often do you want to pull maintenance cleaning.  That's not right after shooting but cleaning how often from just sitting in a safe/case.  Then you can decide what works tor you.  Just keep in mind, to inspect regular.  

I bought this specialty oil one time, my God what a nightmare.  It was designed for gun storage.  The damn stuff would gum up, you'd think it was a light coat of cosmoline.  I like the Slip 2000 stuff.  I tried CLP and kept going back to LSA.  LSA, as the guys in the box have discovered, just clings better and more resistant to things like sand.  This Slip 2000 stuff has no cleaning agent (solvent) in there at all so hangs in there even better.  That being said, I still keep some CLP around especially the little squirt bottles.  Its a fine oil for frequent field use, firing and cleaning often, which what it was designed for.

Tj