I usually only take 1. Sometimes 2 - a .22 and another.
Of course my range is 60yds from my front door, so if I change my mind I can always go back and trade.
But I think if I were driving further it would still be only 1 or 2. I like working with them 1 at a time to really get familiar with them, and work on specifics.
si vis pacem para bellum