On the subject of bearings, Most of you probably don't know what kind of bearings you have. About the only way for you to know would be to have replaced those bearings. If you have sealed bearings, and you keep pumping grease into it, you will probably blow the seals, and then you have an unsealed bearing. Some say that they are greasing every couple days, or hours. Seems like a waste to me. The bearings actually run in the oil extracted from the grease.
If you really want to know what the spindle looks like when you think it needs grease, take the time to break down the spindle and bearings and take a look, analyze the situation and go from there . It's your gun and your machine, do as you wish.
If you search the internet for over greasing , there are many articles on the subject.
