Never used the Winchester #5's out of my sp10 , I did use the Nitro H20213 in straight #5's hevishot I would get 170-180 with those out of a tighter 685 choke -
I used to use the 3 ounce lead nitro loads in nickel #5 and shot around 160-170, if memory serves me well , it was a slower fps load than the other loads mentioned