I've never used anything but factory tubes for shooting birdshot, but I did have a dedicated buckshot gun built when I still lived in the southeast. Took a remington 870 and told the gunsmith I wanted a shotgun that would shoot 00 buckshot as tight as possible.
He shortened the barrel to 21" as I requested and threaded it for a improved modified true-choke tube. He was right. The best shooting buckshot gun I've ever owned. Tight even paterns out to 50 yards. Just the ticket in those Florida swamps. Regards, Byron
