Once you've mastered your iron sights, it's time to start exploring your options for advanced optics to use on your tactical carbine rifle. There are lots of choices on the market, driven by over a decade at war in urban areas. When selecting optics, I go by a couple general guidelines:
- Optics selection needs to be purpose-driven. The optics you want for urban combat are not the same as those for woodland combat, and neither of those are the same as for hunting.
- Good optics are expensive, and quality is important, especially when lives are at stake. You generally get what you pay for. Expect to pay $350-1000 for quality unmagnified "reflex" combat optics, $400-800 for dedicated magnifiers for use behind those reflex sights, and $1000-5000 for precision tactical rifle scopes. You may also spend several hundred dollars on quality mounts, bases, and other accessories.
- A lighted reticle is not a necessity, but has advantages. The color will be more likely to stand out against subdued or camouflaged targets, and is especially effective in dawn/dusk twilight. A lighted reticle typically uses batteries, and last anywhere from 400 hours (e.g. EOTech) to 10,000 hours (e.g. Aimpoint), though some designs utilize fiber-optics and constantly-glowing tritium (e.g. Trijicon, ~8 year life). If you use Night Vision (NV) in your operations, be sure to choose an illuminated reticle that is specifically designed to be NV-compatible.
- Close in, speed is critical in combat. At distance, you have some stand-off to take more accurate shots, or even shoot again if necessary. So decide on the spectrum of ranges you would intend to engage with that particular weapon, and choose optics that favor the speed for the closer end of that spectrum. We are favoring the closer distances of our working ranges, so that we have a wider field of view, are more situationally aware, and engage more quickly. The corollary is that if you choose optics that favor longer distances, you are realistically limiting the combat effective application of that weapon system to longer ranges.
- Iron sights are the great 80%/20% solution. They will let a competent marksman engage 0-300m with a high degree of success. Iron sights are sturdy, cheap, and don't require batteries to operate. Any combat firearm should have iron sights on it, even if they are backups to more elaborate optical aiming devices.
- For any weapon that will potentially be used at CQC ranges (<=30m), only use unmagnified "reflex" combat optics (e.g. EOTech holographic weapon sights, Aimpoint red-dot sights, etc.)
- Fixed-power magnified combat optics, typically in the 3-6x range, give a rifleman enhanced capabilities in the 100-600m range. 600m is starting to stretch to the practical lethality limits of the 5.56mm cartridge, so going to a higher-powered magnification isn't necessary. Remember to favor closer distances.
- High-magnification precision shooting optics, often variable-power in the 4-20x range, are designed for working farther out, in the 300-1000m+ range. The average marksman will need at least an 15x magnification to accurately differentiate whether a person at 950m is carrying a weapon or a tool (e.g. rifle vs. shovel).
- There are a few products that try to help you get the "best of both worlds" or compromise:
- Some magnified optics are available with reflex optics mounted on top of the tube (e.g. Leupold HAMR + Delta Point, Trijicon ACOG + RMR).
- You can get custom mounts that attach a reflex optic to the top of a magnified optic's tube (e.g. LaRue Tactical Burris/Docter Optic and Trijicon RMR Ring Mount - LT788).
- You can get 45° offset iron sights (e.g. Dueck Defense Rapid Transition Sight [RTS]), picatinny rails, and reflex sight mounts, that hang the sights off the side of the rifle. These only require canting the rifle to access the sights, which is fast and intuitive.
- Some variable-power magnified optics can go down to 1x, effectively turning it into an unmagnified red-dot combat optic. One particularly novel application of this is the 1-6x (GRSC) Norden Performance Combat Rifle Scope (CRS), which has a reticle, with both a chevron and stadia lines, that zooms in and out with magnification. At 1x the reticle looks similar to a red-dot, but at 6x you see a full ballistic-compensating reticle.
- You can get dedicated magnifiers (e.g. EOTech G33.STS), that sit behind reflex optics, and detach or swing out of the way during CQC. When utilized, these magnify both the target and the reticle. So if your combat optic has a 2MOA (e.g. covering 2" @ 100 yards, 12" @ 600 yards, etc.) aiming dot, adding a 3x magnifier will have the same proportional 2MOA dot (e.g. covering 2" @ 100 yards, 12" @ 600 yards, etc.) . In contrast, a normal variable power scope only zooms the image, so at low power your reticle may cover the entire target, and at high power the reticle only covers a small area.
I personally prefer the EOTech sights, partly because of how short the viewing window's (hood) depth is (e.g. it's not like looking through a tube, for easier two-eyes-open shooting). The Trijicon SRS and Aimpoint PRO are really nice too. I have also attached a great 6-page whitepaper below, that includes a lot of really great tips for setting up and using your optics properly.
 AR15 Optics- Considerations, Tips, and TTPs.pdf | [By CPT Luke Slatton, MDTS Training] | 319 kB |