Just stay seated for about 1 minute. When you stand up your weapon will be down. Maybe more than a minute, but that's how it worked in the Beta

I really hope this is in the game. Ever since the E3 trailer seeing them with there weapons lowered running, jumping and able to walk around. I really liked this little detail and I think it makes a big differences. Makes everyone seem a bit more life like, not like when your always aiming down scope. This to me feels like everyone are puppets or lifeless mannequin's. I don't know if during the Beta when you were idle you lowered your weapon, I didn't notice but again for a little detail I really hope it makes it to the game.

Yeah, I was hanging out sitting while playing with friends, and I left to go get some soda, then when I got back and stood back up my weapon was lowered. I have no idea if it was a button I pressed or anything. My weapon didn't go back to normal until I melee'd (or shooting would work, too). It is possible, though, we just have to find out how.