I have a lot of data from Ballistics products for 2 3/4.
The load I use for ducks is 1 OZ
Active 2 3/4 hull, CCI-209 Primer, 26 grains of Steel powder, CSD 20 wad. OS card roll crimped
10500 PSI 1400 muzzle Velocity
There is also a Fiocchi load of Steel 27 grains Fio 616 primer CSD 20 wad
10800 psi 1440 fps
I use number 5 bismuth
There are some 7/8 loads as well. Let me know if you need any other data.