I see that a lot of people have problems with this trophy and I often get questions about it. So I want to points some things out.
The best way to go for this trophy is by just playing through the game and check weapon crates EVERY 5 HOURS. Because every 5 hours you can get a orange weapon from a weapon crate. That's always. You can't get 2 orange weapons in a row or 2 within 1 hour (unless you use the glitch, but I'm not sure if it will counts towards the trophy) Assuming you need 5 weapons and 5 x 5 is 25 hours. I think you will put 25 hours in the game with 1 character, so just be sure you open a weapon crate every 5 hours. And there are lots of weapon crates to be found. Can't miss it. If you happen to not get the trophy after you finished with your main character. Then you can either keep playing with your main character till the next weapon. Or you can work on the trophy for completing Act I with all the 4 characters. If you take it slow, you'll play for 5 hours with a character in Act I.
About drops from zombies. I don't know exactly if there also is a 5 hour timer for orange weapon drops from zombies, but I do know that if you get one, it will reset the 5 hour time for a weapon crate. Always pick those weapons up, they count towards the trophy.
But what doesn't count towards the trophy?
- Quest rewards
- Bought in stores
- Dropped/traded with other players.
I hope this is clear for everyone and they understand more about the trophy
Any more questions, feel free to ask me.