I raised to 800 (close enough?) Bet sizing is an issue for me sometimes, I'm trying to counter a tendency to overbet, and my first thought was to make it 1300...Initial better folds (he had an underpair apparently) and sb calls the extra 500
turn is

SB checks....
You are trying to counter a tendency to overbet. But don't you think this is a situation where overbetting is actually better? You raise villain's 300 by 500 more...so tell me what hand you are trying to represent with that bet that doesn't include a 10 like Mondatoo said? If you had the straight draw or air would you raise 500 more? No you wouldn't, so why raise 500 more. Just cos you have a tendency to overbet doesn't mean overbetting should be avoided in every situation.
Not sure what the advice is here. Are you suggesting that 500 wasn't enough? Would 600 make a difference? How much would?
Based on my knowledge of the villain I'd have almost had to shove the flop to get him off his draw....
Not posting the result for obv reasons