A lot of the AR guys are using Mobil 1 synthetic on their guns. I plan to do the same when my economy size bottle of hoppes runs out.
You won't be disappointed. It works great and saves you a bunch of cash.
Alot of guys think that a cleaner or lube has to say "gun" on it. Think about it for a minute though...
A gun is just some moving metal parts. The BEST lube you are going to find for moving metal parts is MOTOR OIL. I don't care how fast you can do a mag dump. You are not going to make a gun cycle as fast as a piston moves in an engine. Motor oil is way cheaper and way better than any "gun" oil.
And just in case that fact doesn't piss enough internet gun experts off, here is another one for you...
High-dollar gun cleaners are a rip-off. Go to the Walmart automotive department and get a couple cans of their cheapest BRAKE CLEANER. You will be amazed how well it works on your guns at less than half the price of "gun" cleaner.