With PERFECT wind conditions, the right shooter, and the grace of God, yes.
250 feet shouldn't be much of a problem if what they say it shoots like is true, but out past that, you will need to spend some time with it.
300 feet is an incredibly long shot for airsoft, and there really are not that many people who have the rifle and skill to do it consistently, which is the key word, you might be able to get 4/10 shots at 300 feet with a lot of work, but that is not consistent enough to really call that a skirmish-able distance.