I recently bought a Remington 870 Magnum Express for home defense. It is a great shotgun and I am very happy with my purchase. The ammo I purchased is 00 buck 2 3/4 shells. Today my friend asked me about what choke I have on it and I had no idea what he was talking about. He explained that they were things things that people screwed onto the end of shotgun barrels to vary the spread of their shot at different ranges. I have cleaned, disassembled, did maintenance on, fired, and taught with hundreds of Mossberg 590s when I was in the Navy and we did not use chokes and I don't recall that word ever being used in conversation or PMS (Planned Maintenance System) cards. I never went duck hunting growing up, only big game such as deer, elk, moose, bear, cougar, big horn sheep, etc., so I have a few questions that may sound newbish. I noticed some unusual threading at the end of my Remington 870 Magnum Express, so I believe there is a choke already installed from the previous owner. Why do some shotguns have chokes and others do not? Is it a combat vs. non-combat thing? Are chokes only designed for bird hunting? Should I remove my choke for home defense? Is it safe to use 00 buck with chokes or are they only designed for bird shot? Thanks for taking the time to educate this shotgun newbie. Here is a link to the Mossberg 590 we used in the Navy. http://world.guns.ru/shotgun/sh04-e.htm *Edit* One last quick question, are there any legal ramifications for removing the plug from the magazine, as long as I am not duck hunting?