I spend a lot of time messing with scopes that qualify as LPV: Low Power Variable. This term really came about when decent quality 1-4x scopes finally came down in price to the point where mere mortals can buy them.
Now, the market is absolutely flooded with LPVs of all sorts made on every continent except for Africa and Antarctica. As is usually the case, the lowest priced ones are not very good and even some comparatively expensive ones are not great. The first really excellent one was probably S&B Short Dot 1.1-4×20 which came about some time in mid-to-late 90s when Hans Bender was still the CEO of S&B and found the project interesting. The basic idea was to make a scope that effectively worked like a red dot sight on low power and could be dialed up if the situation required a precision shot at a distance where a standard issue Aimpoint wasn’t quite sufficient.
That meant that at low power you needed a very visible reticle (either very bold etched design or very bright illumination or both) and a magnification of 1x or close. There are other considerations, but fundamentally if you have a flat and relatively distortion free FOV with a very visible aiming point, you can run the scope on 1x just about as fast as you can run an Aimpoint or a similar red dot sight. As far as red dot sights go, my favorite is Shield SIS, which I prefer to the Aimpoint and Trijicon, so I spend a fair amount of time practicing with it. As I am about to publish another article on LPVs (this time on 1-8x designs that are sorta state of the art at the moment), I got a chance to compare how they do on 1x compared to Shield SIS. When done right, they do really well.
While the industry has really gone toward very high erector ratio scopes, with 1-8x being the current preferred configuration, it is always important to remember that the reason these scope exist is their performance at 1x. Everything else is secondary. When designing a very high erector ratio scope, exit pupil and performance at 1x are often compromised. Alternatively, I have also seen designs where in order to keep 1x performance viable, high magnification performance is compromised.
Now, as LPVs evolve they get better across the board, but some compromises will always remain. For example, consider that an award for the SDMR scope just went to Sig Tango6 1-6×24 FFP scope, despite the fact that there is a slew of 1-8x scopes available. I am not privy to how that decision was made, but if I were a betting man, I would bet that they went with a 1-6x scope because of price and performance on 1x.
The specific Sig scope that won the award is very similar to the current production scope and I am sure the production models will incorporate its features soon enough. The SDMR scope has different outside finish, BDC-type reticle and brighter illumination. It will also be assembled in the US. I have a fair amount of experience with Tango6 scopes and like them. Naturally, I also like that they seem to be running discounts on them every once in a while. Here is a link to the configuration I like at the moment. This is probably similar to the scope selected for the SDMR program.
I am going to stay away from a discussion of FFP vs SFP reticles since I covered it here, but every time I hear someone talk about reticle in LPV scopes someone comes up with: “Well, I only use it at 1x and 6x”, or whatever the top power is. I do not necessarily agree with that approach because with the smallish 24mm objective lens diameter, there is a good reason to dial the magnification down to 4x or so for low light use. That is really the reason I lean toward FFP designs for 1-6x and higher erector ration scopes.
However, if I could get a large enough exit pupil on 6x, I would absolutely agree that all you need is 1x and 6x, assuming that you can switch between them quickly enough.
Now, we are getting to the real reason I am writing this. Most of us do not spend a lot of time clearing buildings and running high speed drills. However, with the state of the art AR-15 these days being both light and accurate, I see more and more people really push the distances at which these guns are shot. Once distance shooting becomes more important a decent LPV is a viable option, but not an optimal one.
Enter the 1x/6x or 1x/10x concept. I have been talking on and off about what I call a poor man’s 1x/10x setup that I have been using on my 308Win AR for years, which is nothing more than a SWFA SSHD 10×42 scope with TPS’ CORA ring that supports a miniature red dot sight at a 45 degree angle. In this picture, I have a Docter Quicksight on it, but that was mostly an experiment in how a very short sight window will work. Quicksight is really designed for shotguns and for a carbine application, I would lean toward something like Shield RMS or Meopta Meosight or something similar.
In the past, I have tried this same setup with the same scope with other red dot sights, like Leupodl Deltapoint and others.
Interestingly, this whole setup weighs about as much as a good 1-6x or 1-8x scope, although it is bulkier. It looks a little out of place on a 16″ carbine, but works surprisingly well.
It does offer me a vastly superior level of high magnification performance. There is also some redundancy in that if the primary scope breaks, I still have the red dot that is brought into action by rotating the rifle just a little bit. No need to re-adjust my hold on the rifle to make adjustments.
Now, 10x is a bit more than I would want in a general purpose scope, but that is what I had on hand and it works fine. If I were going for more of an ultimate compromise, I’d be looking at a high quality 6x scope and the one that Cameraland has an exclusive one is probably the best one ever made. Doug from Cameraland has somehow convinced S&B to make a run of PM II 6×42 scopes for him. There are not cheap, but if you want the best 6x scope in the world, this is pretty much it. Add a compact red dot sight to it in a 45 degree mount and you have the capability of low range variable, except with 6x performance that absolute smokes every LPV ever made.