Not really small. 15 yards is about right for buck shot. The stuff is for riots in phone booths. 4 buck is better than 00 though. More pellets. 6mm diameter.
The really important part is to aim, not just point. You absolutely must pattern the gun too. The box o' truth guys did this.
http://www.theboxotruth.com/the-box-...shot-patterns/
You'll likely get the confidence with one or two practice shots.