Bolt cut-out is for the angled back bolt on a M7 stock vs straight down on a 600 as far as I remember. You might end up with a bigger cut-out to make it work, which is cosmetic in my opinion. I installed a M722 into a M700 stock and had the similar modifications, but the rifle worked fine for years. In my case the safety was also a bit different, but doubt that is an issue in your case. Good luck with it!