I shoot a flat base wadcutter from 38 cases over Bullseye with good accuracy. I've had no luck with wadcutters in 357 cases, and have not tried them in maxi. I do get good accuracy in 357 cases with 160 gr. flatnose, with gas check. These are shot as they drop from the mold, approx. .358. I worked them up for my pistol for a hog round, and they shoot to about 2" in the Handi.
I've shot mostly 180 XTP's i the maxi cases, as this has been my most accurate bullet so far. Loads were worked up with H110.
If you're shooting hard cast "store boughts", the above posters are correct. Speed them up a little at a time, watching for signs of high pressure.