most ballistics calculators are decent enough, I use Sierra Infinity out to 1500 yds in Norway and was bang on target with a new rifle. The real issue is getting good BC numbers , get the Lutz G7 numbers and put that in your calculator.
Ballistic Coefficient Tables
But at 400 who cares really, it's a flat shooting bullet, the drop is peanuts..that's almost point blank range really..
Wind reading will be more important with such light bullets.
Diff between various calculators is next to nothing, splitting hairs at 400 yds
Anyway, try reading wind in a Norwegian Fjord with nothing but rocks and turbulence..