Mid-to-heavy weight precision carbines are often just as compact as the lightweight carbines, but are a fair bit heavier owing to the thicker barrel made with precision in mind. Recce barrel profile is a good example of something used in these rifles and they invariably come with free-floated handguards. Until comparatively recently, this class of rifles did not exist, but it is growing in popularity. These are somewhat general purpose weapons since they are maneuverable enough for CQB, while allowing very precise fire when called upon. They cover the same engagement distances as the lightweight carbines and extend it further out to 400-500 yards as necessary. The sighting system therefore, should be versatile enough to cover a variety of ranges and be a “jack of all trades”, so to speak.
To start off, I have to admit that this is easily my favourite AR variant out there, so I have spent a lot of time considering the sighting systems for it. This rifle is supposed to combine compactness and precision, so it may be called upon to satisfy the broadest range of applications of all ARs and the sighting system is supposed to be similarly versatile.
When people talk about how a particular rifle handles, they all too often focus on weight a bit more than they should. However, a short rifle, even if it is not a featherweight, can handle exceptionally well and ARs with 14.5” to 16’” barrels often fall in that last category.
A precision carbine can be the same thing as a lightweight carbine if you have one that happened to be unusually precise. That is what happened to me, more or less: I set out to build the lightest possible AR carbine with a piston gas system which turned out to be so accurate that I slapped a scope on it and decided to use it as a precision carbine. It is the rifle at the top of the following picture, shown next to another AR I have that is sporting a long range scope on it.
The scope on the carbine is the recently released SWFA SS 1-6x24, but any good quality 1-4x24 or 1-6x24 makes a good fit. The SS runs around $1k and while not cheap offers a lot for the money.
Not too long ago I spent some time testing Vortex PST 1-4x24 and set it up on another precision carbine for for the testing.
The 1-4x24 PST is a decidedly less expensive scope retailing at around $450 - $500. Still, I could comfortably use it out to the practical limits of this rifle, which happened to be around 500 yards.
Yet another option (if you have some money to burn) is the much more expensive IOR 1-10x26.
I think you are getting the drift of where I am going with this: an optimal scope for the precision carbine is a variable design that starts out at 1x and goes up to anywhere between 4x and 10x depending on your price range.
These scopes are usually equipped with fairly sophisticated reticles that allow for quick target engagement at 1x and easy holdover at higher magnifications. There has been a lot of development recently in higher erector ratio scopes, so the 1-4x24s are typically older designs, while 1-6x, 1-7x, 1-8x, and 1-10x are considerably newer. Lower erector ratio scopes are often better at 1x, so keep the intended use in mind as you go through different models.
As of mid 2013, here are the scopes that I like in this category, segregated by price.
Under $500: there a great variety of Chinese 1-4x24 scopes in this price range and the only oneс I really like (and that seem to be manufactured quite consistently) is the Leatherwood CMR 1-4x24 that retails for $300 - $350 and Hawke Endurance 30 1.25-4.5x24 that is under $300. The Hawke comes with a simple but serviceable #4 reticle. Keep in mind that Hawke also makes a 1-4x24 which has a different optical system that is less well worked out.
Right around $500, there are two very respectable designs that I have a fair amount of mileage with: Vortex Viper PST 1-4x24 and Leatherwood (Hi-Lux) CMR4 1-4x24. The PST is very popular scope and for a good reason: it offers a good assortment of reticles, good glass and very solid mechanics. The CMR4 is a higher end version of the CMR with better optics and more solid turrets. If you like complicated reticles, take a good look at the CMR4. It offers a lot of information. However, at 1x, the PST reticles offer faster target acquisition since they have thicker features.
Moving up in price, your options open up a bit more. For around $800, there is the 1-4x24 version of the SWFA SS which has a well designed Front Focal Plane (FFP) reticle. All other scopes I have mentioned so far have Second Focal Plane (SFP) reticles, so if you plan to use reticle holdover, you should be mindful of magnification. A good SFP option in this price range is Sightron S3 1-7x24. I have not yet tested this scope, but I have seen it and while I am not enamored with the reticle they use it seems like a solid design overall. If you like simpler reticle design, you should be taking a close look at Trijicon Accupoint 1-4x24 with its tritium/fiberoptic illumination. It is not optimal for longer range shooting, but very fast close up.
In the $1000 to $1250 price range, you have several very competent 1-6x24 or similar options. Since I like FFP scopes I am partial to the SWFA SS 1-6x24 and GRSC/Norden Performance 1-6x24 scopes. That having been said, if your preferences lean toward SFP reticles, Vortex Razor HD Gen II 1-6x24 is most definitely worth a look. The Razor has phenomenally wide field of view and very bright reticle illumination. It is very fast to deploy and seems to be very popular with competition shooters.
At $1500 and up prices, you have a variety of offerings from all the high end brands and by and large they are all good scopes. They all have their strengths and weaknesses (mostly strengths), so if this is the price range you are looking at, shoot me an e-mail with your requirements and I’ll try to walk you through it. I have not tested all of these, but looked at most of them. Kahles 1-6x24 is one of the easiest scopes to get behind I have seen to date. It is lightweight and has bright illumination, so I expect it to do well with competition shooters. March’s new 1-8x24 that I am testing right now, leans more toward precision shooting, while still being quite compact and light. I think their reticle needs work, but it is serviceable. Leupold was probably the first to market with their 1-8x24 CQBSS and it seems like a very respectable piece. There are a few other 1-8x24 scopes out there worth taking a look at: Premier, S&B and US Optics come to mind. IOR seems to be the only one with a 1-10x26, although it has some tunneling at low end, so it is really a 1.25-10x26 design that is quite heavy to boot. Still, it is a very competent precision scope at 10x, with impressive flexibility owing to the large magnification range.