Why shotgun meter looks like this...

The game’s Heads-Up Display (HUD) featured a shotgun outline that filled and depleted to indicate how much ammo you have left. This way you don’t have to check a number to see how many bullets you still have. Besides the Shotgun doesn’t have a crazy amount of rounds capacity.

Benefits of this HUD style:-

• Quick and clean communication of how many bullets you still have.
• Icon filling/depleting or both together can be used to convey the idea
• Similar to how phones display battery percentage

Since my game is designed to make the Players actively manage reloading thus I put this giant visual in the center and below the Spacebar.