I understand that sentiment, but the motor oil company R&D budgets are way higher than they are for any company specializing in gun oil, so it should not be a surprise that they have a few tricks up their sleeve that gun lube makers don't. Indeed, quite a number of the latter have been developed by trial and error in somebody's basement until they thought they had something good enough to market. What the oil companies can afford to do is actually run the stuff in dozens of engines with carefully measured carbon deposition rates and confirm that it's not their imagination or wishful thinking that a new additive is actually doing something positive. Most small guys just can't do statistically satisfactory testing.
As was said earlier, Mobil 1 may be overqualified as a gun lubricant in most instances, but its the carbon cleaning properties that got Hummer70's attention. One of the problems with carbon is it hardens as it cools, then hardens more over time. That's the reason an M14/M1A gas piston is hard to get carbon out of. But motor oil is designed for a hot environment and doesn't mind going straight into a warm barrel that would evaporate a water-based solvent. The heat makes the additives work faster and attack the carbon before it takes a set. And at 6 or 7 bucks a quart, it's a fraction of the cost of most gun cleaners.
As for copper, that's still a separate cleaning chore.
