I started out with H13 7s and a 660 JH and was putting over 300 in the 10 at 40yrds. With the prices of hevy I've went to lead. The 660 JH did better with lead 5s than 6s. I would definitely get the 660 instead of the 665. I'm happy with mine and prefer the 5s in lead but if I wanted to shoot 6s I would try something in 655 like a Kicks GT. By the way the results I got with lead and the 660 JH was 127 in the 10 with Win. HV 31/2-2oz 5s and 98 in the 10 with Win. HV 31/2-2oz 6s. These shots where at a laserd 40 yrds.