No adcom will compare your hours to someone else's. Likewise, there is no such thing as a cut-off for clinical volunteering hours. Never mind an above average school, you can get into a top school with zero hours. (though obviously it would be inadvisable to try if you can avoid it, I'm just making the point). The number of hours are largely irrelevant. There are two things that matter.
#1 Altruism - I'm not retyping this, so I'll just reference myself:
http://forums.studentdoctor.net/thr...-after-junior-year-off.1113782/#post-16028289
200 hours is not going to impress anyone. It is not atypical for residents/attendings to work 60-100 hours/week, spending 2-3 weeks helping people over the course of a year is a nice gesture, but most of us are looking for a longer term commitment/bigger impact. So, the experience is worth relatively minimal from this perspective.
#2 Clinical experience - We want to know that you know what you are getting into. We don't want you to show up in medical school, pass all of your classes because you are a good student, but don't have the first clue that you actually have no interest in doing what doctors do. To that end, clinical experience/exposure is important, albeit not necessarily mandatory (
@LizzyM would argue closer to mandatory,
@caffeinemia would argue not). The take home point is that the number of hours does not matter. What matters is how it impacted YOU. If you can figure things out in 50 hours, great. If it takes longer, then so be it. I have a hard time believing people when they say that they understand something as complex as medicine after 50 hours of experience. I have been proven wrong, but many of us already having gone through pre-med/medical school/residency will comment about how little we really appreciated what being a doctor was going to be like and every single one of us knows people that didn't know what they were getting into and now regret it or they put a burden on the rest of us because of it.
As an aside, do not tell people that you are going to take a gap year to do something and then tell them that you put in 200 hours. Something doesn't add up.