OK boys, I want my shotgun to perform as it was intended. Open any shotgunning book or ammo flyer from the LGS.
Modified choke at 25 meters let's say? Perfect. I expect about eight or nine of 12 .30 caliber 0-Buckshot pellets in a 30" circle. Energywise, they've lost half their energy and a slug would be more energy-conserving, however, we use shotguns to increase the chances of a hit and to get multiple ones. Only three of those pellets have to hit to effect a probable one-shot kill. Go to 35 meters? The circle is rather larger and now I need four pellets to hit. I, the gun, and the ammo will do that even if the target is moving. That's a shotgun, the whole POINT of it, without "flite-control," a legal solution looking for a problem.
I am continually amazed by this fad of folk wanting to turn their shotguns into rifles for all intent and purpose. That'll go away, eventually, with experience and a little traditional reading. But, in the meantime, if your lawyer, the latest thread, or product-marketing gunzine rag is telling you that "if a proper pattern at the expected range is good a super-tight pattern at farther ranges must be "better," and you accept that generally, consider getting an AR with open-point heads and a red-dot sight instead...
OC? I expect, and want, almost all those pellets in a 30" circle at 15 meters. 30 meters? Those pellets will be in a 5 foot circle at almost 100 feet away. Perfect! That's exactly what I want! With 0-Buck I still expect to have a couple of effective hits at 60 yards on a man-sized target within a 10' pattern. Modified choke? Cuts the diameters of the pattern in half at those ranges if you expect you'll be going out to the maximum effective ranges of the shotgun/buckshot combination (and I wouldn't use a tighter choke on any 0-000 buckshot).