Rather than providing stat bonuses like increased accuracy and damage or reduced recoil, Weapon Mastery in PUBG provides you with unique rewards. These come in the form of charms that are equipped to the left side of a gun’s barrel. PUBG Corp says these charms can never be bought, and each weapon’s Mastery will reward different charms to players.
You earn weapon experience by using weapons, with more points being rewarded for landing difficult shots and surviving longer with the weapon of your choice. There are 100 levels of experience you can earn for a weapon, with every 10 levels moving you up one Mastery Tier. That said, PUBG Corp did not say in its announcement whether these rewards are given when you move up a level or a tier.
PUBG’s Mastery system will be added to the PC test server today, 17 April before it goes fully live on the platform a week later. The mechanic is still in development for PS4 and Xbox One, so players playing on those consoles may have to wait awhile. (Source: PUBG Corp)