I played the new Greece map and noticed a few new weapons and vehicles in some locations. I have gone into game files and figured some of the names out.
WEAPONS
Lockdown:
Type: DMR
Accepts: All Attachments (No Barrels)
Ammo: Lockdown Magazine
Chimera:
Type: Assault Rifle
Accepts: All Attachments
Ammo: Chimera Magazine And All Military Magazines
Backlash:
Type: Shotgun
Accepts: All Except Barrels
Ammo: 12 Gauge Shells
Lancer:
Type: Rocket Launcher (Oh God)
Accepts: All Except Barrels and Grips
Ammo: Lancer Rocket
Kopis:
Type: Handgun
Accepts: Tactical and Barrel
Ammo: Kopis Magazine
VEHICLES
Cerberus:
Type: MLRS Truck
Seats: 2 (1 Gunner)
Ammo: MLRS Box
Chariot:
Type: Jeep
Seats: 5 (1 Gunner)
Ammo: HMG Box
Spartan:
Type: APC
Seats: 6 (1 Gunner)
Ammo: HMG Box
Chinook:
Type: Helicopter (Troop Carry)
Seats: 11
Ammo: N/A
So, do with this info what you want. The MLRS Box will probably be blocked in a while so use it while you can. The Backlash is a secondary so it would be great for snipers. I haven't done enough snooping to figure out if there will be a whole new class of attachments for these weapons or not, but it seems like it. I haven't gotten any Lancer kills but I'll keep it in my inventory to bust open walls. Anyways, Have a nice day and you're welcome!