Hi, I'm looking at getting some 77grain .223 ammo. I noticed that black hill has new and remanufactured ammo. What are the main differences between the two? Is remanufactured as safe as factory new?

Thanks.

The keys to safety and reliability of reloaded ammunition are proper methods and quality control. Black Hills has an excellent reputation and I would expect them to be just as careful with their remanufactured stuff as the new.

The only real variable is where the cases come from and BH probably has regular sources of once-fired stuff.
There could be a safety issue if ammunition was reloaded in cases that were originally fired in oversized chambers with excessive headspace. That's not usually a problem, though, unless the cases are fired and reloaded multiple times.