Semisane - I've never been able to get 300g Deep Curls to shoot as well in my 700ML as most other bullets. In fact, the DC might be the worse shooting bullet I've shot out of it. I can get about 2 1/2 inches at 100 and that's about it. Where I hunt, that's plenty acceptable, but no where near what I would prefer.
Try some Hornady FPBs in it if you can. I've had great luck with them in every gun I've shot them out of. My 700 will shoot those more accuratly than any other bullet I've shot out of it I believe.