Well, I couldn't tell you how much a certian choke spreads at certain ranges because each choke shoots differently.
For a rough idea, a cylinder choke spreads the most, as it is no choke at all, it is used for bird hunting at VERY close range, and for slugs. A skeet or Improved cylinder choke is open as well, but it will give you more effective range. (about 20-30 yds) and a modified (30-40 yds) and full(35+)
For a defender gun, you can't beat a Winchester model 1300 defender in a 12 or 20 gauge, personally I would choose the 20 gauge, its more comfortable to shoot and it will work as good as a 12 gauge. Use a cylinder choke if you wont the most spread.
For a rough idea, a cylinder choke spreads the most, as it is no choke at all, it is used for bird hunting at VERY close range, and for slugs. A skeet or Improved cylinder choke is open as well, but it will give you more effective range. (about 20-30 yds) and a modified (30-40 yds) and full(35+)
For a defender gun, you can't beat a Winchester model 1300 defender in a 12 or 20 gauge, personally I would choose the 20 gauge, its more comfortable to shoot and it will work as good as a 12 gauge. Use a cylinder choke if you wont the most spread.