Don't worry about getting all the rounds out of your mags....switch after 4 rounds if it makes sense...reload on the move
Shoot on the move whenever possible....stopped feet = slow....at least be shooting coming into a position and be leaving while still shooting...you'll need to practice shooting on the move, but watch the big dogs...they all do it....
I made "B" class by running and stopping, but have figured out to make "A" I need to shoot on the move more....2 more points and I'm there
And Like the others said...if you have to go there anyway wait til you're closer...if you can eliminate a stop then take the longer shot