I was talking about if you see someone on your property. If someone broke into your house that is different, but if you see someone on your land trespassing as in hunting without your permission or whatever I don't think it is wise to approach that person. I still think you should call the police and get them involved. Also there is a difference between someone in your house and someone out hunting on your property without your permission. If someone broke into your house you have no option but to defend yourself, if you drive to your property or even the property your house is on you call the police and don't put your life on the line and not to mention your family will be in the house unprotected.
I can also see where your coming from when you said coming up on someone unkowingly, that situation you got to what you got to do then. I have had that happen to me a few times when I came up on someone sitting in my deer stand and by then calling the police is no option if the crap hit the fan. I just held my ground and hoped for the best, luckily it went my way.