The question really is "can you, from a solid position such as you'd use in the field, shoot groups small enough at 400 yards to keep them all in the vitals". The rifle's capability is only part of this, especially as measured in groups shot from a bench at 100 yards. Your ability to shoot, to judge distance and wind (and adjust for them), to adopt a good solid position, to control your breathing, all come into play.
Having said that, if the rifle can't shoot somewhere close to 1 moa from a bench, consistently (not just 3 rounds that one time) you are making it hard for yourself to reach out to 400 under hunting conditions.
