The Leupold Mark 4 line of tactical scopes has been a mainstay in the tactical scope market for over 30 years now. For many years Leupold probably had more high quality tactical scopes available than any other maker on the market. Their original Mark 4 Ultra was a fixed 10x40mm scope developed for military use and is an extremely rugged scope. The US Army adopted it for use on the M24 SWS where it still continues to serve. They also have a 16x40mm version which was designed for extreme range use with a huge amount of vertical adjustments. Since the Mk4 Ultra, Leupold has taken some of their commercial models and turned them into Mark 4 tactical scopes and while they do not have all of the same features as their military Ultra scopes, they have continued to be some good upper mid-range scopes. Leupold has also recently joined the very high end tactical scope market with their Mark 6 and Mark 8 series of scopes. Over the years we at Sniper Central have probably used more Leupold tactical scopes than any of the other brands, but we have only done a single full review of the Leupold scope that is used on the US Army M110 SASS rifle. We thought it might be a good time to take an in depth look at one of the basic midline Mark 4 scopes. The 4.5-14x50mm model is one of the more popular models used by many Law Enforcement agencies in the USA and we thought this would be a good representation of the Mark 4 lineup. We elected to bring in a standard Mark 4 LR/T 4.5-14x50mm with M1 knobs and a Mildot reticle for this review.
Leupold & Stevens, or more commonly known as just Leupold, has been around since 1907 and is a fifth generation family owned American based company located in Beaverton Oregon. They were originally founded as a survey equipment company which is what they did through the First World War and great depression. Leupold was an innovator in water level recording equipment in those early years and it was during World Ward 2 that they also worked on Navy optics and learned a great deal about water and weather proofing optics. It wasn’t until after the Second World War that they branched off into the rifle scope making business and then a few years later they used some knowledge gained from working on military optics to introduce the first nitrogen purged rifle scope. Nitrogen purging is where all of the air is removed from the internal of a scope and then replaced by pure nitrogen, the result is a scope that will not fog internally. Over the years since then, Leupold has introduced many other innovations that we mostly take for granted in modern day scopes, such as the duplex reticle.
Leupold was quick to adopt the concept of tactical rifle scopes for sniping, first for the military and then soon after developing scopes specific for the law enforcement community as well. Today they have many different scopes across several different tactical lines available for use by snipers. The Mark 4 line of scopes is probably considered their more traditional bread and butter line of tactical scopes and the most popular. The Mark 4 Long Range/Tactical (LR/T) 4.5-14x50mm scope we are reviewing here is a common scope found on Law Enforcement rifles as well as some other longer range applications as well. The scope arrives nicely packaged in the traditional Leupold Mark 4 box and includes Butler Creek flip up caps, with the Leupold name on them, instruction manual, small allen wrench for the knobs, and warranty information. The packaging is professional quality and goes a long way to protecting the scope as it finds its way to the end user’s hands.
The scope tube is a 30mm diameter tube and is made of aircraft grade aluminum and is machined as a single piece for durability. The scope is actually fairly short at just 12.5″ with the bell of the scope having a fairly steep angle to it. This short length can provide some mounting challenges for long action rifles, but there is a generous amount of eye relief (3.5-4.5″) that does help since typically the scope must be mounted fairly far forward to allow the bell to clear the Picatinny rail on long action rifles. With the longer eye relief of the scope, this is typically not a major problem, but something to be aware of.
The exterior finish on the scope is a nice matte black anodizing that is very nicely applied over the entire scope. The finish on these Mark 4 scopes tends to hold up nicely through continued use. The overall look and feel of the scope is one of quality and the shorter length and steeper angle of the bell does make it appear compact and purposeful without the “huge scope” look of many new high end scopes, including ones from Leupold.
The traditional eyepiece that Leupold uses on their Mark 4 scopes is a non-fast focus adjustable eyepiece with a locking ring. To focus the reticle for a particular diopter setting, the lock ring is loosened and then the eyepiece is rotated however many times is required until the reticle is in sharp focus. This is done with the scope pointed at a blank wall or other surface without detail, so only the reticle is in focus. Once the eyepiece is adjusted, then the lock ring is tightened back up. The eyepiece rotates smoothly, at least with a new scope out of the box. Over time we have seen these eyepieces get a bit stiff as some grime builds up on the threads from prolonged use in the field. Once freed up again all typically returns back to normal. There is no rubber ring around the back edge of the eyepiece so if a scope “kiss” happens, the results are typically bloody, but with the amount of eye relief available to mount the scope far enough forward, this is typically not an issue with these scopes.
In front of the eye piece is the magnification adjustment ring. The ring itself has serrations on it to help provide some grip when adjusting the power and there is a larger protrusion as well to help. The power ring is marked from 4.5 up to 14x with several iterations through the spectrum. All of the markings on the scope are in slightly off-white color and are easily seen. The power numbers are slightly tilted toward the eyepiece so the operator does not have to move his or her head very far in order to get a power reading on the ring. There is a single white dot on the top of the scope that acts as the indicator mark to know what power the scope is set to. The power ring has a proper amount of resistance to it to insure it stays in place when placed at the desired power setting and it moves smooth and even throughout the full range. There is no mark on any of the numbers to indicate what power the scope needs to be set on for correct mil readings for the reticle, this is required since this scope is a second focal plane scope, but for all Leupold 2nd focal plane tactical scopes, the correct setting is always the highest magnification which is a practical and good way to do it.
We will not claim that Leupold invented the external exposed adjustment knobs, as that can be tracked way back to the long target scopes from the likes of Unertl, Lyman, Redfield and others, and the Unertl USMC 10x Sniper scope had a form or exposed tactical knobs. But for the modern tactical scope, Leupold’s M1 knobs have been an oft copied knob and are one of the more recognizable Leupold tactical traits on their scopes. This Mk4 LR/T scope has the M1 knobs which are a tall external knob with large knurling on top. The elevation knob sits down inside of a protective turret that raises about half way up the knob and itself is marked with an easily visible vertical line used as an indication line. That protective turret also acts as a horizontal reference point for the nicely marked horizontal lines on the “zero” indicator. These horizontal marks indicate how many rotations the knob has been turned to help with returning to zero, this is necessary as the M1 knobs do not have a zero stop feature available. Each click is .25 MOA and the clicks have a positive and slightly muted feel to them combined with an audible click as well. During testing the clicks were able to be felt while wearing gloves which is a nice feature. There are 15 MOA of adjustment per revolution and while Leupold claims the scope has 72 MOA of adjustment, it is widely known that that is an understatement. This test sample had 110 MOA of vertical adjustment which is a very good amount.
The windage knob is the identical size and shape as the elevation knob and it to sits inside of a mid-height protective turret as well. The markings are a nice off-white color, just as they are on the elevation knob and the clicks only count up in one direction, right in this case. Again there is 15 MOA of adjustment per revolution and the windage adjustments are easily made with the nice easy to grip knurled knob and the overall shape and clicks themselves are very nice. One additional feature we really appreciate on both the elevation and windage knobs is that there is a single, larger, set screw in the knurled part of the knob. It only requires loosening that one screw and then easily slipping the knob to the corrected zero and then retightening only that one screw. It is very fast and easy and infinitely adjustable to allow perfect alignment of the indicator markings once the scope is zeroed. Also, for those that are wondering, Leupold does offer MIL clicks on their scopes as well, it is known as the M5 knobs and they are the same as the M1 knobs here except configured to be .1 MIL clicks instead of .25 MOA.
Most all of the Mk4 scopes have a side focus, or parallax adjustment, which this one does. The focus knob is a different size and shape than the elevation and windage knob, it being shorter, wider diameter, and having much smaller knurled features on the top. The knob is marked with dots to indicate the range, the larger dots meaning the scope will be focused closer in while the dots get smaller as the range moves out. There is one final infinity mark at the far end of the markings. The focus knob is smooth throughout the adjustment range and offers a moderate amount of resistance and stays where you place it.
With the focus knob on the side, there are no controls further forward on the scope and it just nicely blends into the 50mm bell which is threaded for sunshades, though the scope does not come with one. With the examination of the features completed it was time to run the scope through the shooting tests. We had a FN SPR FBI rifle here for evaluation and this scope is a common scope found on the FBI SWAT sniper rifles so we thought this would be a good matchup for an evaluation. The FN SPR comes with a 20 MOA base mounted on the rifle so that made that part of it easy, we then used a set of Nightforce Ultralite 30mm medium height rings. The Ultralite rings are a titanium alloy and are a very high quality, yet lightweight and durable set of rings. We mounted the scope up to the rifle using these rings and headed out to the range to conduct our normal battery of shooting tests. Conditions for testing were 37 degrees with moderate rain, mixed occasionally with heavy rain, and light wind. These were actually good conditions for testing a scope as it will test the antifog capability as well as test the optics of a scope in tough conditions.
With this Leupold scope missing a fast focus eyepiece, it is worthwhile to take the additional time to adjust the eyepiece so that the reticle is clear and sharp, and this pays dividends in the field with a nice clear picture and crisp reticle. As normal for scope zeroing, we turn the knob down 20 MOA and fire one shot at a target at 25 yards. The scope easily focused at the close range and the shot was recorded. Making the scope corrections needed we shifted to 100 yards where it again easily focused and we zeroed the scope to the rifle at that distance, slipped the knobs to zero and began the testing phase. Repeatability and accuracy of the adjustments was tested shooting through the box, making adjustments to shoot rounds at all corners of a 6 MOA box in this case. The 5th set of rounds ending back at the starting point of the test, and as they should, the rounds where right on top of the first. The next test we like to do is adjust 20 MOA in any one direction, left in this case, and then measure the distance between the groups to test accuracy of the clicks. The measured distance between the two groups was 21.5″, which was about 3% greater than it should have been but falls within the accuracy of error of the rifle which was shooting about .5 MOA groups. When we brought the adjustments back to zero and fired another group, it was exactly on top of the first group showing again excellent repeatability.
The long range capability of the scope is excellent with very good optics. Leupold uses index matched lenses on these scopes as well as their high quality coatings and the optics were very clear and sharp from edge to edge with good contrast. The simple mildot reticle is still one of our favorites as it is simple, non-cluttered, and still accurate enough to provide good range estimations with practice. We did find that the long eye relief actually caused us to move the scope forward one notch on the Picatinny rail and this will be a nice attribute on high recoiling rifles. The high amount of elevation adjustments also lends itself well to high powered rifles. Once the scope was zeroed on the SPR at 100 yards, the scope still had 48 MOA of down elevation adjustments as well as 62 MOA of up. That 62 MOA of up is enough to take a .308 rifle to almost 1300 yards while still maintaining a 100 yard zero. Though careful tracking of how many rotations one has adjusted will be necessary!
When it comes to a prototypical mid to high end tactical scope, this Leupold is probably the defacto standard. It is amazing to think that just a decade ago this would have been considered a definite high end scope, but now there are many excellent very high end scopes that have raised the bar, such as those from the likes of Nightforce, Schmidt & Bender, Premier Reticle, US Optics, Hendsoldt, Zeiss, IOR, and the list goes on. But for under $1500 you get a very good scope with all the right features, it is still reasonably sized, is high quality, has very good glass and is US made and supported by an excellent customer service department. Yes, we would like to see a zerostop feature, perhaps a fast focus eyepiece and maybe even higher quality glass, but those are available in the new Mk6 and Mk8 scopes, but for a lot more money. For what it is, these old work horse Mk4 LR/T scopes are still a very good scope and we consider them a good buy.