40, 50, 55? .223 for prairie dogs question

[Questor]

I want low-recoil .223s for my son to shoot on his prairie dog hunt.  I want the least recoil possible and will load them significantlly lighter than maximum. I'm thinking around 3,000fps.  

It's windy there. For shots out to about 250 yards does it make much of a difference-- in terms of wind deflection--  to use 55 grain bullets instead of 40 grain bullets?

The gun will be an Encore rifle with a scope.

[Blackhawk44]

Though not having done it, in your place would look at the 40gr Hornady and Nosler plastic tips and lighter loads of 4198.  These bullets as long as some short 55gr.  With the 4198(for better combustion than the slower ones-doesn't need as much resistance for complete burning) should work out fine.   Check the latest manuals.