One major advantage of the AR platform is the ability to easily and reliably mount optics. Another chief advantage of the AR platform is SAWC. If we are concerned with the SAWC of the gun, that doesn't go out the window when we consider optics. There are many optics manufactures that produce extremely high quality optics, but are too heavy for what they provide. (Nightforce and US Optics are two prime examples.) If you find an optic worthy of their name, but they managed to make it a reasonable weight, go for it! But, remember, every ounce counts.
The thinking in favor of using these extremely heavy optics is maximum dependability - like if you were fighting in Iraq or Syria, jumping out of Helos, jumping in and out of APCs, etc. First off, very few people who are buying their own optics are actually doing those things with their own optics. Secondly, how much more dependable or durable are these heavier optics than, say, a Vortex or a Burris? I mean, if you shoot it or run over it with a tank, the brand, quality, and weight really doesn't matter. The best way to determine durability for real-world use is, if you drop the gun and it lands on the optic, will the optic still work and did it hold zero? Based on that definition there are numerous manufactures that fit the bill. Of those manufacturers, who has the best warranty? For my scopes, it seems to always come down to products by a handful of manufacturers, notably including: Vortex and Leupold, and Burris. For Red Dots, obviously the aforementioned manufacturers also make the cut, but I would add Aimpoint and Trijicon, among others.
So, really, what do I recommend? Bear in mind that this is for an AR15, chambered in 5.56, not a Georgia Precision rifle in 300 Win Mag, so these are not meant for extreme long-range. Here's the list, which I plan to update periodically for new products and changes to products:
- Red Dots
- Vortex SPARC II - Tough Red Dot (Shockproof, waterproof, fogproof) that weighs 5.9 oz in a compact size. This isn't the best Red Dot money can buy, but it has Vortex's VIP warranty and a pricepoint around $200. The battery lasts a long time (not like Aimpoint, but really good), it has both an automatic shut off set at 12 hours (not so short it cuts off while you're shooting) and an on/off button to be sure you aren't wasting battery life. I also like the temperature range of this optic. Some brands have poor operational temperature range, but this will work in most environments. And, it can exactly co-witnesses with iron sights or be adjusted to a lower 1/3 if you'd like. This is honestly one of the most rugged optics I've ever owned, so for any Marines out there, I would strongly consider this option.
- Holosun HE503CU - This sight is meant to remind you of the Eotech "Doughnut of Death." It
is solar recharging, has IP67submerssion rating, up 50,000 hours of continuous use on a single battery, and it's extremely lightweight at 3oz. At $350ish, these are cheap enough to afford and provide you with great performance for your money.
- Bushnell TRS-25 - A very cheap, but solid, option. You can typically pick these up for $75 or so, depending on the political climate. They have a lifetime warranty and are excellent optics for the money. A gun snob might turn up their nose at this, but they work very well and are simple to use. These have adjustable brightness and an affirmative "off" setting, so you will know when they are off. (Which, helps if you are putting them in storage or setting them aside and don't want to waste the battery.) At about 4oz, they are very lightweight, as well.
- Vortex Venom - The Venom is all of 1.1 oz! That is incredible. It's also waterproof, shockproof, and fogproof. And, it has Vortex's warranty, which is such an asset. So, what is an "offset" red dot? If your primary optic is a scope, this is a great 45 degree offset option for close-range because of the weight and size. This will help when you are transitioning between close and long-range targets. (For instance, the red dot can have a 25 yd zero, while you zero your scope at 100 yards for distance shooting.) This could be a primary red dot as well, but you would need an additional mount to provide "co-witness" height for the optic. If you want the lightest weight possible, this is a great contender for that title.
- Holosun HS507C - This Optic, has all the features of it's bigger brother up above, but in a tiny package, making it a perfect secondary/offset optic. It
is solar recharging, has IP67submerssion rating, only 1.5oz, and again offers the "Doughnut of Death" dot pattern. At $300ish, it's a reasonable price for a great optic.
- Vortex Strike Eagle 1-8x24 - Shockproof? Check. Waterproof? Check. Fogproof? Check. It has excellent glass for the price and it is only 10" and 17oz. Such a good scope for the money and the warranty is outstanding - it is hard to find a better value. This optic is an amazing value, offering a quick-turn magnification knob and clear glass. As a Low-Power Variable Optic (LPVO), it is ideal for use in CQB and medium-range shooting. The biggest drawback is that it is significantly heavier than a red dot. It is also Second Focal Plane - which means the reticle's marked adjustments are only accurate at the highest magnification. However, for fast adjustments to point of aim, doing a hold-over with the BDC Reticle is easy. For greater distance with a budget optic, such as reaching out to 800 yards on a .308 rifle, use a larger magnification member of this family of scopes.
- Red Dots
- Aimpoint Micro H-2 - 3 oz and 5 years of continuous use battery life. Shockproof, waterproof, and fogproof. Usable in temperatures ranging from -30°C and +60°C. The weight, battery life, temperature range, and dependability make this an awesome choice, especially for set ups where this is the primary (only) optic. The problem: they aren't cheap. As a secondary optic, they're a little heavy, but they still have great benefits, like a mind-blowing 5 years of continuous use for the battery. And, never forget that Aimpoints are almost indestructible.
- Holosun HS512C - This sight is meant to remind you of the Eotech "Doughnut of Death." It is solar recharging, has IP67submerssion rating, up 50,000 hours of continuous use on a single battery, and it's very rugged. It's also a Holographic sight, which significantly reduces Parallax and downrange illumination helping you shoot accurately from off-platform shooting positions and avoiding giving away your position. For under $500, this is a great choice.
- Trijicon RMR - This is a rich man's Vortex Venom. Why spend the extra money? 4 years of continuous use battery life and the company reputation. Is that worth it? I don't know, but I would rather not spend $600 on a secondary red dot. If money was no object, I'd consider this based on the battery life, number of mounting options, and company reputation. In my experience, these are preferred by competition pistol shooters because of the added accuracy potential of the 1 MOA dot and the high quality manufacturing/reliability of this optic.
- Leupold DeltaPoint Pro - Known for quality, high-end glass, durability, and a great warranty, Leupold Optics are always a good investment. Honestly, having said that, with what Holosun and Vortex are offering in terms of price, battery life, features, and/or warranty, companies like Leupold are going to need to up their game to be able to compete. But, this offering is a reliable 2oz optic with great warranty, durability, lots of mounting options, and great optical clarity for under $500.
- Vortex Razor HD Gen III 1-10x24 - This is, quite literally, the best thing Vortex has ever made. The glass is amazing and the magnification range is the best available on the market for an intermediate-range weapon like and AR15. If you have the money and the need to buy (arguably) the best Low Power Variable Optic on the market, this is it. There is no downside, from weight to performance to durability to warranty, you won't be sorry to own this optic. 21oz for an optic with this type of glass and 10x magnification is extraordinarily light. Oh, and it's First Focal Plane, so you get accurate reticle data at any magnification. Just a great optic, and it better be for $3500.