which combo would you try first?

[tha bugman]

3" 2oz Magblend 5,6,7 or 4, 5, 7?

[Candyman]

Not what you asked but I had lots of success with straight 6's in my Encore.

[taylorjones20]

Out of the two options I would use the 5,6,7 if they pattern well out of your setup.

[the Ward]

5,6,7s. I've had great patterns with those out of different guns and chokes. I think the 4 shot would take up room that is better filled with the smaller size shot for a denser pattern. I haven't tried the 4,5,7s, so I don't know how they would compare to the 5,6,7s, but I can't see them putting up better #s in the 10" at 40 with less shot.