Another vote for SST but every gun likes different ammo.
My pump mossy loved Winchester Bri sabots , when I switched to remington 1187 the only ammo it liked was SST and I would get a clover group at 75yrds with it.
I was a little anal about SST , matching batch numbers when buying boxes and then bringing them home and sorting shells by weight for each season.
All deer were one shot kills with SST and usually didnt take a second step.