Forum:Best methods to farm legit guns?

Hi guys, little bit of a dumb question I'm sure but I wanted to get the input of the informed masses to see if I'm doing the right thing. I know you can farm equipment doing New Haven chest runs, but I was just wondering what was the best method for farming up some of the best items in the game. I realise getting everything legit will take longer then just finding someone to dupe copies for me but I'd like to be able to find this stuff myself. Thanks in advance for the help!