TFB Review: Kahles K540i Riflescope – The 40x Game Changer?
This is a review of the brand new Kahles K540i DLR premium riflescope. The K540i is designed for precision shooting at extreme ranges, boasting an impressive 5-40x magnification range. TFB is the only international publication chosen to review this riflescope before its official release.
Kahles Riflescopes @ TFB:
TFB Review: Kahles K18i Riflescope with IPSC Reticle (incl. Comparison) TFB Review: Kahles K525i DLR 5-25×56 Riflescope TFB Interview: Raine Peltokoski – World Champion Senior – IPSC The LWRCI REPR Mk II Elite with Kahles K328i Riflescope
We’ll dive deeper into the details further down the review, but here are some of the highlights: The new Kahles K540i features optics with a 40% wider field of view, compared to Kahles’ K525i at 25x magnification. This is great for enhanced situational awareness and target transitions. The zoom range is 8x. Windage adjustment is available on either side, left or right, featuring Kahles’ TWIST GUARD rotation protection. Integrated parallax adjustment in the elevation turret, adjustable from 20 meters to infinity.
The 540i has 160 clicks per rotation with precise, repeatable accuracy and well-defined tactile feedback. The K540i DLR version which I’ve used here has extra large turret lettering for easy and fast reading and 100 clicks per rotation. The reason why I choose to review the DLR version (Dynamic Long Range) is that it’s what I use on my fairly new Kahles K328i (mounted on my LWRCI AR10), and most of my long-range shooting is in PRS or DMR style competitions where the DLR options make more sense.
Below: The Kahles K540i DLR in a Spuhr SP- 6002 mount.
For transparency, this riflescope will be sent back to Kahles. “My” particular K540i DLR is one of the first built, but I have not found any pre-production issues, nor do I feel I got a golden sample. In fact, just as I finished this review I learned that the scope here is from a normal production run. I own a variety of Kahles riflescopes already, the K18i-2 LPVO and the K328i both of which I paid for, but the majority of my optics are of other brands.
The main purpose of this review is to see whether the K540i lives up to its promises, try it with two different brands of scope mounts – and while doing so show you a set of beautiful images.
Kahles – Full Lineup For The Future
The Kahles K624i was one of the kings in optics many years ago, but times change and the development and competition continue. Kahles now has a really nice lineup to meet customers and competition, with scopes like the K18i, K18i-2, K318i, K525i, K328i and now the K540i. Let’s not forget the K1050 either. The naming kind of reminds me of how BMW used to name their models…
K540i Build Quality and Design – Turret and Controls
Like any of the new Kahles riflescopes, the K540i exudes craftsmanship. Initially, I spoke to Kahles’ product manager, and it’s easy to understand his enthusiasm for the product. It’s another robust construction with a sleek anodized finish, and it’s clear this optic is built to withstand harsh conditions. Anyone used to Kahles will feel right at home with the feel and quality of the controls. I’m relatively new to Kahles, so it takes me some time to get used to the parallax spinner. With the DLR turret (fewer clicks per rotation) the clicks are super-easy to feel, and they are very tactile and exact. The clicks for the side adjustment are good, no complaints really, but not as superb as the DLR turret. I guess very few click for wind during a stage anyway, so I am just being very picky as one should be at this level of quality and price. The illumination control is on the right side of my K540i DLR and works perfectly. The main tower on “my” 540i is CCW, with one click being 0.1 MRAD (1 cm @ 100 meters).
My only complaint here is the friction of the magnification wheel. It’s just a tiny bit too stiff, but it could be something that improves with time and use. Make sure you order your K540i with the throw lever – thank me later.
K540i Optics
The glass offers edge-to-edge clarity with exceptional sharpness, ensuring that every detail downrange is crystal clear. As far as I can tell without going into the lab (that I don’t have), there is minimal distortion, even at high magnifications. Instead of focusing on the steel target, I tried to focus on a small pebble in the sand just behind and looked through different brands of similar optics. The K540i is certainly at the highest level, so it shouldn’t disappoint picky buyers. Kahles describes the eye box as exceptionally comfortable even at 40x, and while it is good I can’t say it was any better than the others. I would need more time behind the gun to change my verdict, as I didn’t do any competitions with it. I have done a DMR competition and some hunting with the K328i DLR, and I have no complaints, so I have no doubts the K540i DLR will do just fine.
A large eye box is what everyone wants, but is it really needed since when we’re shooting at 30-40x magnification we’re usually in our very best shooting positions anyway?
Killflash ARD, because it looks cool. Never underestimate the sensation of looking cool.
And if you can, suppress everything.
K540i – The Mounts For Ø36 mm Tube
Sorry to bore you with the metal, but no scope is better than its mount and we have two highly interesting brands and options here. One is from Area 419, with their 36 mm tube, 39 mm (1.53”) and 0 MOA offset. The other is the Spuhr SP- 6002 mount, with Ø36, H38mm and 0 MIL offset. There are of course other options out there, but it gives you a guideline to start. A 36 mm tube is a good beginning anyway…and you might need to go for a cantilever model depending on your rifle.
Area 419 supplies their mount in a very nice plastic container, and the tool/bit that fits the screws – very appreciated! It feels premium, but once the mount leaves the box there’s really no need to keep it.
Area 419 uses a pin to index the parts, and probably protect it from recoil as well.
Spuhr has a different approach, which is patented, with 45-degree cuts. The knife is a Benchmade SOCP, and probably sharper than the optics.
The attachment surface to the Picatinny rail. Again, two ways of doing it. Area 419 uses the screws for clamping and recoil. Spuhr uses the screws for clamping and has a slot for the recoil management.
On the rifle this is how it might look, Area 419 vs. Spuhr QD Cantilever on the K328i (front).
The Kahles K540i follows the trend with large oculars, now becoming more popular with manufacturers. Here is the standard “throw lever”.
White On Black Or Black On White?
The elevation turret has an integrated parallax adjustment, adjustable from 20 meters to infinity. The readings are clear – but I always wondered if black on white wouldn’t improve visibility even more. It will drive cost I’m sure, but product developers please mark my words.
K540i vs ZCO840. Note the ePaper DOPE card, more on that in another article. The right chassis is a Spuhr SICS with a 6XC barrel – it shoots pretty straight.
Kahles K540i Optics and Performance – Winter Solstice
First of all, a disclaimer. I did this test during December 2024 and January 2025, in a period where the sun shows itself much less than anyone wants. Midsummer is a happy time for an optics review, but this one was done over the winter solstice with a lot of clouds and sometimes winter conditions. But hard times create strong men, or was it optics?
I’ve taken the K540i to the range a few times, and I’ve had it mounted on a tripod all by itself to do the best possible to evaluate it. To benchmark and get a second opinion, I brought a friend and a bunch of other similar optics. We’re not going to go deep into the benchmark minefield, but I will briefly touch on the subject.
Below: The Kahles K540i DLR vs. Zero Compromise Optics ZCO840 vs. Schmidt & Bender 5-45×56 PM II. We also had the Schmidt & Bender 5-25x PM II around, and while it certainly still works just fine it’s starting to belong to an older era, just like the Kahles K624i.
Below: Some of the best optics on the market.
Below: Kahles K540i DLR vs. Zero Compromise Optics ZCO840. The ZCO is obviously customized by a competitor, with an Aimpoint ACRO secondary red dot in a Spuhr mount.
K540i Reticle Choices
The K540i is available in the following reticles: AMR, MSR2/Ki, SKMR4+.
The K540i DRL (shown here) is available in the following reticles: SKMR+, SKMR4+.
“My” reticle is the SKMR4+. The K540i has an illuminated reticle in the first focal plane. I try to do my best, but it’s always very difficult to do any riflescopes and their reticles any kind of justice through a camera. It will always look different in front of your own eyes.
Below: SKMR4+ reticle. Paper at 300 meters, and steel targets at about 312 meters. The drawback with all super-zooms is that the reticle at low magnifications is usually just useable as an overview rather than something you can use as a sight.
Below: This is probably more of the image and magnification you’re looking for.
I zoomed in on the image below just to show you how poor the weather was. The “milk” is actually rain and snow in combination.
To compare, below is the ZCO840. I do not remember which magnification levels I used in different photos, sorry, so don’t make too deep conclusions between the optics. Also, the weather switched quickly and it was freezing outside. I’d rather take my photos in the summer…
Below: The Schmidt & Bender 5-45×56 PM II, GR2ID reticle. This is at 45x, and you can read the full review here.
A Short Benchmark – Are Kahles’ Claims For Field Of View & Eyebox True?
At full magnification, the image quality of the optics between K540i and ZCO840i are very similar. They both look great! However, the owner of the ZCO840i said that he would buy the Kahles if he bought another one, but he still thought that the eyebox of the ZCO840 was greater. I think this conclusion is very precise. They are both a little better than the S&B in terms of image, but the S&B has a few other qualities.
However, in terms of Field Of View, I measured the following (larger is better):
ZCO840i – 4.8 MIL
S&B5-45 – 5.0 MIL (at around 40x)
K540i DLR – 6.4 MIL
The conclusion is that the Kahles has 33% more FOV than the ZCO at 40x magnification, which is quite a huge difference. I would certainly allow Kahles to call that a “Game Changer”, and perhaps they were only very humble when they compared it to their own K525i in the marketing material.
Below: The K540i DLR on a Ruger Precision Rifle with the new True Ballistic Radar Chronograph. Don’t miss the Vector X and my extensive review: Vectronix Vector X – Premium Laser Rangefinder Binocular.
Kahles K540i – The options
Because we are TFB, we like to do things properly and reply to as many questions our readers possibly may have. Therefore I suggested to Kahles that instead of sending a naked 540i, let’s include all the options, and I mean everything.
So Kahles included a bubble level, the Flip-Up covers for the objective and ocular, an enlarged parallax spinner, a sun shield and the must-have throw lever. And just for it to look cool, there’s a Killflash ARD as well.
The Killflash ARD below, with all of the options mounted.
The Microtech knife has a nice Kahles-orange about it, but it’s not an option!
Note that with the super-spinner for parallax, it’s not possible to mount a forward red dot (or similar).
My only complaint with the options is very minor – it was not possible to mount the sun shield all the way in. The Killflash worked, so it could be the threading on the sunshield or something else. I didn’t want to force it and destroy any of the threadings, but perhaps a drop of oil could be the remedy?
While the bubble level below certainly works, I do prefer any of the modern electronic levels like MDT’s Send It.
Below: More Killflash ARD, for Anti-Reflection Device. A must-have so that those counter-snipers can’t see you. Picky ones will note that the surface finish is not an exact match.
At TFB we have a love for tubes, some filled with lenses that make you see better and further, and some that suppress the noise. This is the A-TEC Marksman, and it mounts on A-Tec’s own muzzle brake. I found the suppressor to work great!
This is the Ruger Precision Rifle ready for competition, with the MDT Lightweight CkyePod Bipod.
DATASHEET – The Kahles K540i / K540i DLR
Instead of listing the data sheet here’s an image that I hope comes out in a readable manner.
Things of beauty. The OD Green LWRCI REPR Mk II Elite with a Kahles K328i DLR and a Ruger Precision Rifle with a Kahles K540i DLR.
The Kahles K540i is made in Austria. The warranty is 10 years according to the datasheet, and 2 for the electronics.
Killflash and Area 419 mount on the Ruger. Spuhr QD mount for the K328i on the LWRCI.
Kahles K540i – Verdict and Recommendations
The Kahles 540i is a premium scope tailored for long-range precision shooters (and hunters) who demand unparalleled optical performance. Remember that “long-range” is very subjective – I know .22LR competitors who shoot groups and compete with similar types of magnification levels and optics at distances below 300 meters. Most people think 1000 meters plus, but that does not have to be the case for these types of optics.
The K540i and K540i DLR are not cheap, but grade-A optics never are – forget the bargains! I usually have longer times with products that I review, and not during the darkest times of winter, but I feel certain that I can recommend the 540i based on a long number of conclusions. If anything, my love of the image quality might just increase as we get more hours of sun every day.
This K540i reticle works great, I just wish I was a lot better at keeping the center dot exactly where I want it and faster. The distance is 311 meters, so feel free to measure and calculate the size of the steel targets. They’re probably smaller than you think, but my friend convinced me we need a lot of anxiety when we train.
The 56 mm objective of the K540i is going to gather a little bit more light than the K328i with its 3,5-28×50, and some long-range hunters might feel a need to upgrade already.
The ocular is most likely one of the biggest secrets behind the K540i’s high performance. You may have noticed that several manufacturers have super-sized their oculars lately. I’m not an optical designer, but let me presume this is the biggest secret behind the increased Field Of View and improved eyeboxes lately. Some of my good old benchmarks have been crushed recently, and it’s thanks to products like the ones from Kahles.
Price: The price is €4,500 incl. VAT in Europe and $4,600 in the US.
Kahles K540i – Pros and Cons
Pros:
Most likely the best Field Of View in the industry.Outstanding magnification range – 5-40x.The controls are excellent.Get the DLR version if your focus is DMR/PRS/Dynamic shooting.Excellent clarity across the magnification range, including at maximum zoom.Good selection of options.
Cons:
High price point, but not necessarily more expensive than similar competitors.The throw lever is a recommended option.Users of MOA may have to wait for a reticle (MOAK+).
Find out more at: https://www.kahles.at/us/