From the time I first took to the field deer hunting at 8 years old, until I bought my first deer rifle when I was 18 years old, I used an old Ithaca "Super Single" 20 ga that my dad bought for me and my brothers used for $15. Never any real long shots that I remember as it only had a single bead, but I never remember anything walking away from it. More than enough power for whitetails, and probably even black bear.
I do remember as a young kid that it did kick like a mule with a 3" slug as the gun weighed very little.
I may cut the barrel down on it now and have it tapped for scope mounts for my kids to use.
LAZER