cr500

Go 1/4 and 1/2 as modern lead shells give tighter groups than
older paper wad shells. You can also tighten patterns by changing
shells if you do some patern testing and know what shells work
in your gun.

As to forcing cones, I am not sure whether it would change the pattern
that much - only recoil but I would change the chokes first.

500 Nitro