Hey, I was wondering if it's possible to get scopes from later games (for guns from later games) to work in World at War, for example I have the Hybrid Sight in World at War. And how would I do it?

the same as you would setup an underbarrel grenade launcher, or even the m1garand with launcher. Just set it up as an alt-weapon, except for the switching anims where it puts on the grenade you use the animations where it switches the scope's. Then in the weaponfile just set a new ADS-fov etc.
You can make the guns share ammo and stuff like that, so it's 95% the same..

the same as you would setup an underbarrel grenade launcher, or even the m1garand with launcher. Just set it up as an alt-weapon, except for the switching anims where it puts on the grenade you use the animations where it switches the scope's. Then in the weaponfile just set a new ADS-fov etc.
You can make the guns share ammo and stuff like that, so it's 95% the same..

Hmm is there perhaps a tutorial about it? I have never set up an underbarrel grenade launcher either.

You can look at this topic, at the bottom of the OP there's:

Setting up an alt-weapon:

http://ugx-mods.com/forum/index.php?topic=3006.0


That should make it work for the setup and animation wise.
You need to mess around with the weapon files for your specific settings, might want to keep the ammo_name and clip_name the same so they share ammo, and use the scope-switching-anims for the alt-raise and alt-drop anims , etc stuff like that