I generally use 7 1/2 for a real good pattern in my T/C super 14.....
"(a) With a trap, snare, net, rifle,
pistol, swivel gun, shotgun larger than 10 gauge, punt gun, battery gun, machinegun, fish hook, poison, drug, explosive, or stupefying substance;"
I believe the content of this is meant for a pistol firing a solid projectile, not shot...I would email your local Fish & Game department and ask...then you have it in writing if they say yes.. bird laws are pretty subjective...for instance where I live you can use a .410 for waterfowl as long as you dont use lead shot...but you cant use a 410 for wild turkey under any circumstances...and we cant hunt dove...but we hunt crows with the 410's sometimes..and many, many people shoot crows with rifles..the .17 HMR being the new crow round of choice for many....Im not a lawyer...but I slept at a Best Western