Slower velocity and smaller shot charges normally pattern better due to less set-back in the bottom of the shot charge. When the shell goes off the bottom layers of pellets can compress and deform when the charge and speed and greater. That does not mean the slower velocity and charge weight do not deform pellets, they just deform less which allows them to maintain a tighter shot string. The less deformation, the fewer flyers. Another thing that has been proved through testing is unless there is a 150 FPS difference in speed there is no noticeable difference in lead on your target.
For me, the only time I load over 1 oz is when I'm loading 10g and that's only because I can.
I keep the speeds under 1200 too and it all comes together. When you find a combo that works, stay with it.
