UrbanMan replies: Mil-dot scopes provide a way for the user to range his target. The basic concept here is the user knows the magnification setting on the scope for which to use the mil-dots as a ranging estimate. The distance between each Mil-dots are one Mil. Each Mil is about 3.5 inches at 100 yards to keep it simple.
Therefore if you were looking through your scope at a 3.5 inch index card, and that card measured from one Mil-Dot to the next (center to center), the distance would be 100 yards....as one mil equals 3.5 inches at 100 yards.
Actually, one mil equals 3.6 inches at 100 yards but I'm rounding down to make it easy for this post, for readers to understand and do the math.
If you were looking at a man sized target, lets say 18 inches from waist to chin and the distance that sight picture (from waist to chin) took up 5 Mil-Dots in your scope, then that distance would be 100 yards....Five mils equals 17.5 inches at 100 yards.
It's just plain math from here on out. That same man sized target, waist to chin, at 200 yards would take up 2.5 mils or the distance of 2 1/2 dots (center to center) in your scope.
So you pretty much have to know the dimensions, either height or width of your target in order to use the Mil-Dot ranging technique. Having said that, I prefer a Mil-Dot reticle in my bolt rifle scopes, however the only one I currently have is a 4.5x14mm Leupold on my Remington LTR.
As far as observation equipment for Urban Survival, having a good pair of binoculars are always handy. I own five binos. Probably won't be buying anymore soon, but you can tell the value I place in them. I have 10x50mm, 8x56mm, 7x50mm, 10x42mm and a small set, 8x24mm. Not counting the quality of lens and the coating, you can divide the magnification (the first number) into the second number (the size of the objective lens) and the higher than number the better light gathering or light transmission capability you'll have.
For instance a 7x50mm gives you a 7.1 factor, whereas the 8x24mm gives you 3.0. The 7x50mm will take in more light and therefore are more usable during periods of lower light (dawn and dusk).
Spotting scopes are generally bigger, more cumbersome but provide higher magnification. When using anything over a 10 power magnification, you will need to use a rest or a tripod as the image will dance around too much. I think that spotting scopes are great for observation at long distance, with variable magnifications usually in the 10 to 60 power range, however I think the Urban Survivalist's first priority would be several pair of decent binoculars.
All the binoculars at this page are good kit and fair priced. I own one set of Steiners and two sets of Leupold, but my cheaper binos (Bushnells) have given me good service.
