The disclosed packaging containers may include a body including a sidewall and at least one top flap for at least partially covering an opening of the body when assembled and perforations in the sidewall of the body. The perforations may include a lower perforation having a first end portion and a second end portion; a first side perforation extending upward toward the top flap from the first end portion of the lower perforation; and a second side perforation extending upward from the second end portion of the lower perforation, wherein the first side perforation and the second side perforation converge toward each other as they extend upward from the lower perforation. Various other packaging containers, systems, and methods are also disclosed.