In 2007 when Boss agreed to build my guns I requested a 600. They were only prepared to build a 700. Having fired a 700 holland ( courtesy Winks ) it was too much gun for me to fire. I love to carry my guns and although I only fired the 700 I doubt I could carry it. Boss has a new owner who is happy to complete my original order and the 600 is under way. I find the 600 easier to shoot than the 577.