[MadMax]

I recommend the lightest weight oil you can find on mags and pneumatic seals. Heavier oils can accumulate in the barrel which promotes a symptom I call gun smegma. Accumulated oil can foul your hop up and make it less consistent. Oily surfaces can pick up dust and make a black goo that you don't want in your barrel.

Any lubricant you use to condition your seals will end up getting blasted through your barrel which is why I suggest the lightest lubricant you can find. SUPER SPECIAL AI GBB OIL for teh win! It's 1.5wt.

For metal-metal contact, like slide rails and trigger pivots, silicone oil is crap. Silicone oil offers little film resistance and is very bad at staying in place. I suggest lithium grease available at many R/C hobby shops. Do not use anything like silicone differential grease. While that stuff is thick, it's still at preventing metal-metal contact and it's extremely viscous. It will act like an adhesive under high velocity applications. My preference is to mix some colloidal graphite powder (check Canadian Tire in auto section) with some lithium grease. I apply a light application and action everything manually about a dozen times, then disassemble and wipe it all off. It's messy stuff, but colloidal graphite burnishes into metal surfaces nicely providing slick dry lubrication. The little traces of lithium grease provide additional friction reduction. With little grease to hang onto stuff, I find I get less accumulation of wear particles or dirt.