I'm looking for and need some information about shotgun shells and shooting. Particularly regarding chokes, length of shells, interchangeability, and the safety thereof. Anyone have an explanation or links to read and study? I might have more questions as I learn.
You kind of asked a question akin to "what kind of car do I want"... And nothing else.
Some context?
You want to know about the kinds of chokes that are out there? Like widest to narrowest?
Interchangeability of what? Ammo within certain firearms?
Length of shells is pretty easy. In 12ga, generally speaking, it's 2" (mini shells), 2.75, 3.00, and 3.5. Wouldn't surprise me if there weren't a 3.25 in there, too. And again, generally speaking, you can go "down" in shell length and be OK - but not up. Mileage will vary on if a certain gun will feed certain shells, and certainly will vary on if a semi-auto will cycle shorter/lower powered stuff.
So - can you be any more specific with your questions?
You actually answered the my primary concern. You can shoot 2.5 inch shells in guns made for 3 inch. But not 3 inch shells in one made for 2.5 inch shells. Shorter length is okay but not longer.
I have spent the past 45 minutes reading Google links and got most of the immediate cocerns answered or confirmed what little knowledge I had.