#5 should work fine too. I only use #4 for turkey. But then again, I’ve never strayed from the 2 3/4 shotgun. Still haven’t gone to the 3 inch/3.5 chambers—which is popular for turkey these last couple of decades.
I got a lot of game with the old 2 3/4” shells. The type of hunting I do now is more chaotic. Large geese, large and small ducks and snipe. Steel shot has made me add a couple size to shot and go to 3” shells. I have some of the bismuth and other shot mixes but they are spendy.