Dang! I’ll bet that’s a very effective zombie gun.
Surprisingly tight pattern at 25 yards, considering the barrel is only 18.25” long (as measured from the breechface.) I always leave an extra .25” in case a shotgun gets dropped and the muzzle gets dinged up - that way I still have some metal left to work with and I can re-crown it without making it too short for the minimum 18” required.