I used 00buck for about 20yrs, then started mixing in Carlson's Dead Coyote (bismuth T shot) and Winchester Xtended Range Coyote (bismuth B shot) in the last few years.
For the 00buckshot, a guy needs an improved or light modified choke. Ideally something in the 0.710-0.720" constriction. With buffered buckshot, you can get away with down to around a 0.680", but keep those 0.660" and smaller chokes just for your turkeys.
I've shot buffered 00 buck shot through my Carlson's Dead coyote choke (0.680"), as well as through a TruGlo Gobble Stopper (0.660"), but I tend to get spreading patterns out of my Primos Tightwad (0.655"). Non-buffered shot seems to HATE anything smaller than 0.700 or 0.710".
With the Carlsons Dead Coyote load (Bismuth T shot), it seems like 0.680" is about as tight as it can get. Early on when the dead coyote chokes came out, some where 0.660" and some where 0.680". There were a lot of complaints with the 0.660" chokes, so carlson's would replace them with one of the 0.680" chokes if you mailed it to them. I've had a 0.680" from the jump, so I didn't experience it personally, but I get ideal patterns out of my 0.680" dead coyote, and I get holes in my patterns with my 0.660" and 0.655" Truglo and Primos.
ON THE OTHER HAND:
You COULD just decide what length of shell you want to shoot and then use a Patternmaster choke of the appropriate length (short range for 2 3/4", long range for 3", and Extended range for 3 1/2"). These are not restriction chokes. They run 0.729" clear out to the end, and have multiple nubs inside the mouth that would be approximately the right length that the wad JUST reaches the end of the choke, so it gets jerked off of the rear of the shot column.
I JUST bought mine a few weeks ago, so I'm just getting my preliminary feelings on it. I bought two of them, a 3" and a 3.5" version (long and extended ranges), have been using the long for dove this week, seems to be patterning very well, as I'm knocking dove out of the air.
It's pretty intriguing to think a guy could use ONE choke for any shot he'd want, from 00buck down to 8's (although I think these babies do produce pretty tight patterns, sometimes I want more spread).