Let’s talk about objective lens sizes. 40 to 44mm is pretty standard on a medium variable rifle scope. It’s trendy these days to have large objective lenses of 50, 56, or even 75mm in some cases. In most cases, these are unwarranted, and the largest ones are laughable. Largeobjective lenses will only transmit more useable light than smaller ones if they are set at their highest power in the dimmest conditions. The detriment is comfort and ease of eye alignment. With a properly mounted scope, you should be able to close your eyes, shoulder your gun with a proper, repeatable stock weld (a stock weld is the firm but comfortable and repeatable position of your face on the gun stock), open your eyes, and look directly through the center of your scope every time. Large objective lenses prevent this from happening because of the ring height required to keep such a large lens off your gun barrel. Some scopes require such high mounting that only your chin touches the stock. These scopes are also heavier, clumsier, unwieldy, unbalanced to carry, slower and less comfortable to shoot. Some of these scopes weigh up to an unbelievable 3.5 pounds!
Leupold might have something going on with their new VX-L line of scopes that combine a large objective lens with a contoured bottom that doesn’t interfere with your gun barrel, and lets you mount up to a 56mm lens with low rings!
The larger 30mm main tubes on some tubes are most useful for allowing for a greater range of elevation adjustments, not greater light transmission. In fact, most 30mm scopes have the same size lenses that are in one inch tubes.
Most scopes are fogproof and waterproof. Most scopes have coated lenses. The coatings are expensive and vary in type, number, and quality. It is very possible to have a scope with single coated lenses to greatly outperform a scope with multicoated lenses. It all depends on the quality of the glass and the coatings. Good quality does not come cheap.
The following are accepted terms for coatings:
- Coated: A single layer on at least one lens surface.
- Fully Coated: A single layer on all air to glass surfaces.
- Multicoated: Multiple layers on at least one lens surface.
- Fully Multicoated: Multiple layers on all air to glass surfaces.
Coatings reduce glare, and loss of light due to reflection. More coatings normally lead to better light transmission and sharper contrast.
Another trend today is the sale of anything called “tactical.” Military semi automatic rifles in the hands of advertisement-gobbling civilians often have super-high magnifications on their scopes up to and even including a ridiculous 40 power scope with an absurd 75mm objective lensweighing in at several pounds.
Real military snipers use top quality fixed 10X scopes most often. These have mildot reticles, that in the hands of a practiced individual or team of two, often with calculators, and knowing the approximate size of their target, can estimate distance and hold-over or elevation clicks. Almost all mildot calculations must be made with scopes at their highest power. Fixed power scopes eliminate miscalculations by having a scope set at less than its highest power.
The “mil” in mildot does not mean military. It means milliradian, a unit of measurement for angles.
Stateside law enforcement agencys most often use variable scopes of the highest quality, and mildot type reticles are not often used. They clutter the field of view, and the longest shots almost ever taken are across a street, well under 100 yards. Range estimation is not required.
Mildot reticles in most people’s scopes are nothing but a gimmick and an added expense. They will never use them the way they were designed, which is fine. You can still use them in the field to more accurately estimate hold-over at distances, especially for prairie dogs or plinking, or just because you want it. Buy what you like for any reason. You don’t have to buy or not buy something because of someone else’s opinion.
To get to know how mildots are used as intended, go to this excellent Leupold website and study. Leupold Mil-Dot Instruction Manual
