Secondary Weapon
From WikiRaider
There are five Secondary Weapons in Lara Croft: Relic Run that can be purchased and upgraded either with the in-game currencies Coins or Gems: Crossbow, Shotgun, Dual SMGs, Assault Rifle, and Grenade Launcher. Unlike Lara's Dual Pistols which has unlimited Ammo these weapons have a limited supply that can be refilled by collecting ammo while running through the levels or Ammo Crates in the combat sequences.
Each weapon has first to be bought and than can be updated four times. The last and most powerful upgrade always takes gems.