#4 lead?!? Moses' sandals!! You use 3" magnums too? Ruffed grouse have to be the easiest birds to kill - a half dozen #7.5 is more than enough to do the job. If they're wounded they don't run like Sharptails (THOSE birds need some artillery) they just hit the ground and flutter. Your best bet is a very open choke and lots of little pellets. Target loads are plenty.
Yeah, I'm kinda with Grouse Man on this. 7, 71/2 or 8 for ruffed grouse and woodcock. 6 for preserve pheasant, huns and sharptails, 5 for pheasant. All lead.