[m0ntels]

Got some 00 sitting around and cant find anything to do with it. All the data I'm finding is for different size pellets, even though I always thought 00 was the most common. I'd prefer to use 2 3/4" hulls, as that's what I have on hand, and I wouldnt mind buying a new style wad, but I'd prefer to stay with modern style wads, as that's all I have experience with.

Randy

[Poodleshooter]

I don't have my data on me,so experimentation is in order! :D
Weigh your charge (8 or 9pieces of the OO you have on hand). Convert to ounces from grains. Should be in the neighborhood of 480grs or just under 1-1/8oz with most OO lead pellets (the nominal weight of OO is 54grs ea,but varies considerably by brand). I prefer using established 1-1/8 or 1 1/4oz field load data for starting loads as it adds a margin of safety. Essentially you're only changing the shot size.
Find a variety of load data that matches the powder,primers,hulls and wads you have on hand. Experiment by stacking the buck in the wads to find a wad that handles the load well. Shorter wads are usually necessary. Buckshot will almost always exceed the height of standard shot wads. The important part is that it doesn't exceed the crimpable length. Test the height by loading the starting loads for your given component set,and seeing if the buck stacking allows for a normal star crimp. I prefer 3x3x3 stacking,but it does make for a bumpy hull using regular wads.
With normal wads,don't expect super magnum buckshot performance. Keep it very conservative. I usually can get 1300fps max from my OO buckshot loads. They pattern quite well from a modified choke at 35-45yds. I prefer using Green Dot,though I have used Clays as well.
WAA12R wads will certainly work as they are very short and provide plenty of space,but they have short shot cups and provide rather poor patterns IME.
The WAA12F114 is probably a better choice as it is quite sturdy and roomy,and you may even get good loads from the lighter Fed 12S3s,Rem Fig 8s or WAA12s.
This kind of loading is a little weird,but it sure beats buying expensive bags of cork and felt wads or nitro cards from BPI.