EDITED TO ADD: Due to a few e-mails from readers concerned that even the concept of a 'combat weapon sight' for civilians, and the use of a rifle for defensive purposes, were 'over the top' and verged on paranoia, I'd like to explain why this post was written.
For a start, there are certain situations where US civilians have used (and are using) rifles in defensive situations. To name only a few:
- Ranchers and farmers along our border with Mexico are facing a deluge of illegal immigrants, who are destroying fences, poaching farm animals, and breaking into homes to steal whatever they can - sometimes threaten the occupants too.
- Farmers in the plains face difficulties dealing with predators who menace their animals. They carry a rifle in their farm pickups as a matter of routine. Some of them also face threats from cattle thieves, who'll try to round up a few head, load them into a truck, and be gone before anyone notices them.
- During crises such as the Los Angeles riots of 1992 (referenced in the article below), the aftermath of Hurricane Katrina in New Orleans in 2005, etc., more than a few city-dwellers made use of rifles and shotguns for extended periods to defend themselves, their homes and their businesses. I'm sure there will be similar crises in future.
Other countries have also experienced situations of civil unrest and/or terrorist conflict, during which rifles and shotguns have been (sometimes routinely) used by civilians to defend themselves. I have personal experience of this.
That's why this article was written - to address the admittedly limited, but nevertheless real problem of civilians needing to use a long gun for self-defense, and discuss how best to aim it under the circumstances we're likely to face (which are usually governed by different legal considerations from those affecting military and law enforcement personnel.)
I hope those considerations make it clear that this article is not written from a ninja-wannabe point of view - it's as practical as I can make it.
I had occasion to exchange a few e-mails with former shooting students of mine, who are looking into various sighting options for long guns as they grow older and their eyesight deteriorates. I'm in the same boat, so I know all about the problem . . .
Anyway, we went through the list of options available. If iron sights are problematic, a red dot sight or RDS (also known as a reflector or reflex sight, particularly in more expensive models) can offer a good short- to medium-range alternative. In military service they've produced more and faster hits than iron sights, and their battery life has been greatly extended; but military sights are built to be very rugged, and priced to match (usually in the high hundreds to low thousands of dollars per sight). Unfortunately, cheaper RDS's are often prone to breaking down, and some models consume batteries very quickly. (There's at least one notable lower-cost exception, the Bushnell Trophy TRS-25 (shown below). I currently own 6 of them, using them on both handguns and long guns. It's not an Aimpoint, but it's nevertheless excellent value for money, IMHO.)
Furthermore, the red dot or triangle or other reticle shape can 'fade out' in bright sunlight, making aiming literally a hit-or-miss affair. Conversely, at night the reticle can be so bright as to 'wash out' the view through the sight, calling for a rapid adjustment to a lower intensity level. If people are shooting at you while you try to do this, the delay might be more than merely counter-productive.
However, civilians have a particular legal problem. Military personnel in a combat zone don't have to worry too much about target identification. If they have shots fired at them, and see movement in the place from which the shots came, they can (and usually will) fire back at that movement without hesitation. (Yes, yes, I know there are usually Rules of Engagement telling them to make sure that they only shoot at a clearly identifiable enemy who's visibly armed, yadda, yadda, yadda. If you believe they're going to stick to those rules in the heat of a close-range engagement at night, then you probably also believe in the Tooth Fairy and Santa Claus. BTDT.) Theoretically law enforcement personnel don't have the right to open fire on suspects indiscriminately, but in practice they sometimes do so. (Just look at the three innocent victims shot up by police during the Dorner manhunt last year, or the nine - nine!!! - bystanders injured by police gunfire in a single incident in New York City in 2012. There are many other examples.) You'll note that very seldom do the officers involved suffer seriously negative consequences. The badge protects its own.
Civilians don't have the protection of a uniform to minimize our troubles with the law if we shoot the wrong person. We have to clearly identify our target and confirm that he's definitely a threat before we shoot him, or we're going to be neck-deep in the proverbial brown substance. RDS's (typically unmagnified or with relatively low magnification, usually no more than 2x-4x) won't do much to help us identify a target. If it's nighttime, in a neighborhood filled with contrasting streetlights and deep shadows, or a back yard veiled in darkness, how are you going to be able to say for sure who shot at you? Even in daylight, if a shooter is a few dozen or a few score yards away in a crowd, how are you going to be able to pick out of the mob the one or two individuals who pose a direct and immediate threat to you? (Think of this in the context of the Los Angeles riots of 1992 - see here and here for some first-hand accounts and video recordings.) You can't just shoot into the mass of people - you'll be charged with attempted murder, even if you don't hit anyone. What if someone's taking pot-shots at passersby from the window of an apartment block? Which window? If there are several dozen people at several dozen windows, which one has the gun? How can you tell at a distance? (Obviously, you should be hunting for cover before you try to find out, but the principle remains.)
You won't have time to reach for a pair of binoculars to identify your attacker, then put them down, pick up your rifle, and focus on your target. While you're doing that, he'll still be shooting at you; alternatively, he'll be 'getting out of Dodge' while the going's good. You need a sight that can shorten your decision cycle; help you identify your target more clearly and make the decision to shoot or not to shoot as quickly as possible. This is where the telescopic sight comes into its own. A good-quality variable-power scope can be lightweight, optically sharp, and give you the ability to see much more clearly at a distance by dialing up the power. At night a quality scope will transmit available light reasonably well, enabling you to see into all but the darkest shadows with greater clarity than you'll be able to achieve with the naked eye alone. Furthermore, it doesn't have batteries that can go flat at the worst possible moment (unless your scope has an illuminated reticle for nighttime use - a useful accessory under certain conditions, but not an essential one).
I accept that a telescopic sight's crosshairs are less quickly acquired visually than the dot or other reticle shape of a RDS, particularly in low light conditions. On the other hand, I submit that for civilian use the advantages of a telescopic sight outweigh those of a RDS in all scenarios except close-range rapid fire against multiple opponents - a scenario we're most unlikely to face under normal circumstances. You can train to use a telescopic sight effectively in the latter scenario as well, setting it to its lowest power and using it more as a 'tube sight' than a telescope. (If you use see-through scope mounts or rings you can employ your long gun's iron sights at close range if you wish, reserving the telescopic sight for longer ranges.) If the light's too low to use either telescopic or iron sights, you probably shouldn't be shooting at anything you can't see anyway. If you can't clearly identify a threat, and defend that identification and your actions in court if necessary, you shouldn't be shooting. Period.
Which telescopic sight is best for the purpose? Everyone will have their own answer to that question. Mine is currently the Nikon ProStaff 2-7x32 variable-power scope (shown below).
They're on my .30-30 lever-action rifles and two 5.56x45mm. carbines, and will go on a couple more rifles as and when I can afford to buy additional examples. They serve my needs very well, and I highly recommend this particular model as excellent value for money. They're very clear and sharp, low-power enough for use at close range in urban settings yet high-power enough for use out to the effective range of the cartridge. (I also recommend the Nikon ProStaff 3-9x40 scope with bullet-drop-compensating reticle, if you don't mind a slightly larger and heavier scope.)
Finally, a laser sight can be a very useful addition to a fighting rifle. The trouble is, if there's enough smoke or dust in the air the beam will be visible to the naked eye, pointing out not only its target but also where it came from - in other words, your location. I therefore prefer not to use lasers unless the circumstances are such that concealing my own position no longer matters. At a time like that, I'll take every advantage I can get!