Some people say you can shoot steel or other non-toxic shot out of the older full barrels but I don't think it's recommended.
The generally thicker full barrels do leave you the option of having choke tubes installed. This runs between $80 and $300 bucks depending on who you use. Check out http://www.trulockchokes.com and see what he can do for you.
If you want to use a fixed choke with non-toxic shot I'd look at no more than mod and would rather see improved as non-toxic shot generally patterns better than lead.
The generally thicker full barrels do leave you the option of having choke tubes installed. This runs between $80 and $300 bucks depending on who you use. Check out http://www.trulockchokes.com and see what he can do for you.
If you want to use a fixed choke with non-toxic shot I'd look at no more than mod and would rather see improved as non-toxic shot generally patterns better than lead.