I just acquired an old Remington model 12 pump rifle. Surprising how pricey some of them are. The receiver is not rusted but the bluing is gone. The barrel is very dark. How do I best give it a basic cleaning? Do I have to take it to a gunsmith to determine it's safety or can I just take it to the range? The pump and trigger work and cycle. Do I hurt it if I dry fire it? I'd really like to play around with it.