These are the generalized rules for firearms in Adventurers League.
The DMG lists some other items as firearms too, but pistols, rifles, and muskets are the common ones you may see.
Some people want to play with firearms. Some people don’t want firearms in AL.
Some reasons (that we can surmise) behind the AL admin’s decisions about firearms include:
In any home game, your DM calls the shots on what is or is not allowed. In Adventurers League, the AL admins have that decision power.
The AL admins have “compromised” by allowing firearms in AL, but making it non-trivial to obtain firearms.
When Wizards of the Coast are designing their sourcebooks and adventures, they don’t build the books for Adventurers League. So the AL admins must adapt to what the books do, as the AL admins see fit.
For many, firearms are a too-real link to real world problems, from which they are trying to escape by playing D&D.
Please don’t point a finger and play “What About”. Let’s keep the topic on firearms.
The ALPG 15.3 (pg. 7) says: