so i got a slightly used browning citori and the bottom barrel has an extended improved modified choke but the top has the screw in style and i am not sure what size it is. thise are the only chokes it came with so that is all i can shoot with for now. I was wondering where would be the best place to get a hold of some other extended chokes? the only place that i have been able to find extended chokes were on cheaperthandirt.com and i couldn't find anything different than the imod.