It seems like a simple enough question.  Why else...to determine the distance to your intended target.  Of course this is the most obvious reason we use range finders while bow hunting, but there are several underlying reasons it can be very important to use one. 

You spend time practicing your shots from various distances (or at least you should!) and those distances are usually known i.e. 20 yards, 30 yards, etc. So, when we get out in the field, we also want to know the distance. Why risk putting in all that practice time and then going out where it REALLY matters and just guessing when we could know for sure.

The range finder can actually be a big confidence booster when it comes to bow hunting deer.  Most bows today are fast and can shoot tight groups.  Many, in fact can handle anything from 0 to 30 yards with a single sight pin, however; if that big buck is at 28 yards, I have a lot more confidence knowing that and holding so my arrow will find it's mark.

Another important aspect of the newer model range finders is the downward (or upward) angle compensation adjustment that is built in.  When shooting at steep angles (downward or upward) you will shoot high.  How high depends on the distance and degree of angle.  The actual reason this occurs can be a little confusing, but it equates to your "line of sight" distance being greater than the "actual" (straight line) distance.  There's actually more to it than that, but the important thing to know is that it will happen.  The good news is that the newer range finders have all that figured out and will give you an accurate reading for so you can shoot with confidence.

One more reason to use a range finder when bow hunting deer is to pre-scan the hunting area.  That way you will know, well in advance, when the deer is in your "safe shot" zone.  This zone is different for every hunter.  For me, it's got to be 40 yards or less (preferably less).  If you spend a lot of time shooting at greater distances, then your zone will be bigger.  We've all had the MISSES, (if you haven't, give it time and you will miss!). 

The most important reason I recommend using a range finder when bow hunting deer is to insure a fast, clean, ethical kill.  Shooting at an animal that is simply to far away and wounding it is something we should all strive to avoid.  Making a bad shot because of mis-judging distance is something that we can control.  If there's any doubt, let ‘em walk.

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