Tactical Auto 556mm Same stats as automatic, has a full length rail on top 38 Same stats as automatic, has a full length rail on top 308 Same stats as standard, has a full length rail on top
45 Same stats as standard, has a full length rail on top Tactical 5.56mm Same stats as standard, has a full length rail on top 38 Same stats as standard, has a full length rail on top 308 Slightly less damage than semi-auto counterpart 45 Slightly less damage than semi-auto counterpart Automatic 5.56mm Slightly less damage than semi-auto counterpart 38 Slightly less damage than semi-auto counterpart 308 High damage, longer range, uses hunting rifle magazine. 45 Mid damage, short range, high rate of fire, uses smg size magazine Standard 5.56mm Mid damage, longer range, uses Stanag size magazine. 38 Lesser damage, few recoil, uses smg size magazine. Instead of 16 vanilla receivers that all has the exact same appearence, there are now 16 receivers that offer 4 different calibers with according size and magazines, 2 different type of model and lastly either semi-auto or full-auto.