How to unlock crossbow as there are no scavenger mode servers?

@DavidBowieFan420 hello!
Now, unfortunately, there's no way of unlocking the crossbow without the Scavenger Servers... So, I guess, all you need to do is when you play BF3 give a check on the Server browser and see if there's any... Even if the server is at 0 people, get in and the server should fill in because, in your position, there's another people as well...

If I helped you in any way please hit that "Give XP" button and if I solved your problem please click as "Accept As Answer"..thank you!

-SOS Sir.B