Thank you both
I understand what the issue is now and I'm reading the link that Greg posted which has helped a lot.
I see the purpose of the Game-State and how that is more built around OOP design of Java and this actually helps me out with some other features of my game I was planning. I'll get to work on it right now, thanks again guys
--- Update ---
Just an update of how I got on with the static issue.
I made the GameState class that manages the bullets and bats, then I simply made my gameState object in the main loop. I'm passing the gameState into the parameters that need it such as creating the bullets and adding them to the list and everything seems to be working as intended. I'm pretty sure i'm doing it right anyway
it's more OOP like now at least, without any static variables/methods as they aren't required for what I need.
Thanks for the help guys