Okay, here’s my first idea:
Single shot 4 gauge shotgun. Give it a short barrel.
Let’s call it “C-1 Thumper”, standing for “Cannon-1 Thumper”.
Second idea:
A modified 50 Action Express m1928 sub machine gun. Give it a drum mag.
Let’s call it “M2024 Expert”.
Hope you enjoyed im bored BYEEEEE