One of the things that made the M21 a successful sniping system during the Vietnam War was the ultra-simplistic means of range estimation that would also automatically adjust the scope for ballistic drop at whatever range the scope estimated the target to be at. This was known as the Auto Ranging Telescope, or ART, and it was designed by James Leatherwood. These original ART setups on the M21 used a Redfield 3-9x scope and there were two distinct versions of the setup through the M21’s life time. The Leatherwood name now appears on a very similar setup to the original ART and it is the same concept and even carries the same ART title, but are they as effective as the original? There is only one way to find out.


As mentioned, the Leatherwood name goes quite a ways back and is closely tied to the US Military sniper rifle history due to Jim Leatherwood’s history with the M21. A new crop of Leatherwood scopes came onto the scene several years ago with various different models such as the “Sporter” and others. Fortunately for price, and unfortunately for quality, the scopes are made in China and the initial quality of these early scopes was poor. According to Leatherwood, the quality was unacceptable as they were being pushed down the priority rung behind other larger scope brands, so Leatherwood purchased their own factory in China and the current Hi-Lux/Leatherwood scopes are being produced there. Reports indicate that quality has come up, but it takes time to get it to where they want it.

For those that are not familiar with the concept of the ART scopes, the idea is to zoom in the scope on the target until a specified sized target is bracketed within some indication marks in the scope. The scope is mounted in a specific mount that mechanically raises and lowers the scope while it is being zoomed in so that it will automatically compensate for the ballistic drop while the scope is being zoomed in. The theory is to zoom in until target is bracketed, and then pull the trigger. Of course, windage would need to be compensated for separately, but the range would automatically be taken care of. The original ART-I and ART-II systems were used to great effect by US Army snipers in the Vietnam conflict.


The entire setup comes in a standard scope box but since the mount is an integral part of the overall system, it comes with the scope mounted in the rings and the rings attached to the ART base. The base itself is designed to mount directly to a picatinny style rail, but due to the design of the system, there really is no need to go with a canted base. The package comes with some detailed instructions, scope caps and some small wrenches and wing nuts for the mount. The scope looks fairly standard in terms of modern scopes. The Hi-Lux scope has a single piece aluminum tube that is 1″ in diameter and tapers nicely up to the 44mm objective. The finish is a matte black anodizing with what appears to be laser etching for the markings. The finish is evenly applied and the lettering is clear and readable.

The eyepiece where the ocular lens is housed has a small rubber ring on the end that is intended to help protect the eye in the event that the shooter gets too close to the scope during recoil, but the rubber ring is fairly small and hard and we are not sure how well it will cushion the impact. The eyepiece itself has some mild serrations on it to help with gripping it for when focusing the eyepiece (diopter adjustment). This is not a fast focus eyepiece but rather it takes almost three and a half rotations to cover the full range. The adjustment is not the smoothest we have tested, but it does cover a wide range allowing it to focus for even fairly bad eyes without corrective lenses. There is no locking ring for the eyepiece, though there is probably enough friction to hold it in place for the most part. There are some indication marks in order to log where it should be for each shooter, but the markings are fine, light and difficult to reference. It is usually better to just lock it and forget.

In front of the fairly short eye piece is the zoom and cam setup that is the crux of the ART system. As we have mentioned, the ART system is linked to the zoom ring of the scope so that as the operator zooms the scope onto the target so that the brackets on the reticle cover a specific sized target, the cam system mechanically raises and lowers the rear of the scope to auto compensate for the range. This cam system has some indicator marks on the top that are used to adjust the cam to match it more closely with whatever cartridge you are using. From the rear of the scope, on the front face of this cam, there is clearly marked both the magnification power and what range the target is at. The cam has some knurls on it for a finger hold, and they are needed as the system is stiff as it adjusts both the magnification of the scope as well as mechanically opposes some friction in order to raise or lower the rear of the scope. The cam mechanism is fairly large and adds considerable heft and weight to the rear of the scope. On top of cam system are some screws that are used to loosen and move the cam and range ring to adjust them to your specific rifle. Right in front of the cam is a screw that angles in to lock the cam at a fixed range if so desired, this prevents moving the cam and zoom ring.


In front of the ART cam setup are the traditional elevation and windage knobs. These knobs are the size of a traditional target style knob and they do have dust covers. The elevation knob is tall, but there are only markings on the bottom because there are four additional “rings” with a slot in them that can be moved around, using the tip of a bullet, to be used as additional zero indicators. The idea is to be able to use the scope on several rifles and have their respective zeros marked by these little rings. For tactical use, this is really not a practical or even desirable feature as scopes are usually setup specifically for one rifle and it would be impractical to try and utilize a single scope among many rifles. Perhaps for a hunting rifle this may work and save money, but not in our line of work. With that being said, the elevation knob has 15 MOA of adjustment per revolution and a total of 80 MOA of adjustment, which is 20 more than the advertised 60 MOA. The clicks themselves are fairly positive with a fairly loud audible click. There is a bit of knob movement, or slop, between the clicks before it actually engages the internal mechanisms. The top of the knob has some aggressive serrations and it is easy to get a good grip and adjust the knob. The cam mechanism can be disengaged to allow the use of the scope knobs in a traditional manner if so desired.

The windage knob is the same size and shape of the elevation knob and has the same four rings used for setting zeros for additional rifles. The clicks are the same and there is 15 MOA of adjustment per revolution. The numbers do count up in both directions with the cross-over happening at 7.5 MOA which provides a good amount of windage compensation before issues may come up with knowing where you are at on the knob. One thing of note on both the elevation and windage knob is that they are marked as being .25″ at 100 yards but yet the manual indicates they are .25 moa. While .25 inches vs. .25 MOA is very close, they are not identical and at longer ranges the difference is significant and should be noted. Leatherwood should probably change the markings in either the book or on the knob to correctly identify the actual distance and to synch up the manual to scope.


There is no adjustable objective on this scope and with a conservative 2.5-10x magnification range you can get away without one and not be hurt if you use a good repeatable cheek weld. It does simplify the operation of the scope and does also help keep the price down. The bell of the scope that houses the objective lens is threaded for a sunshade though it would need to be purchased separately.

The optics on the scope are actually fairly good for the price of the scope. The image is bright and clear from edge to edge, though the reticle is not as crisply defined as in others and the reticle lines are fairly thick, especially at lower magnifications. The extra thickness does help with picking up the reticle in low light conditions, but it hurts when trying to place accurate shots. Everything is always a compromise. The reticle is a mildot reticle in the 2nd focal plane which means the scope needs to be set at 10x to use the mildot reticle in the traditional fashion. This of course would also set the elevation of the cam for 1000 meters so care needs to be taken. The reticle is a bit different than a traditional mildot reticle in that it only extends 4 mils from the center crosshair intersection, instead of the traditional 5 mils. The other difference is the addition of some hash marks near the center; these hash marks are at the half mil mark and are used for bracketing the target for use with the range finding ART system. Zoom in until the hashes cover 1 meter on the target, and then presto, the range is auto compensated for.


For our operational tests we mounted the scope onto our Remington 700P test mule which is chambered in .308 Win and has the standard 26″ barrel and HS precision stock. The rifle typically shoots a bit better than .75 MOA with good match ammo. Since a 20 MOA picatinny rail is always mounted to the rifle we left it on and mounted the Leatherwood scope directly to the rail. The manual indicates not to tighten the side cross nuts tighter than hand strength which is what we did. Right away you will notice that the scope is mounted very high up off of the rifle which we typically do not like; it is better to mount the scope as low as possible without it touching the barrel. In this case we did not have any other option. The mount mated up without any problems with our base and there are even some screws on the front ring of the setup to allow for large windage adjustments using the base and rings if it was needed. One word of caution, like most “hand tight” setups we have used in the past, they do not hold. The cross screws loosened within 20 rounds and we had to monitor them continually through the rest of the testing. Using the provided wing nuts does eliminate this problem according to several other Leatherwood users we were in contact with.


Before we tested the ART system, we wanted to run the scope through the traditional tests that we do for all our scope reviews. In these regards the scope performed only okay. The 6 MOA box test was fairly accurate but the last group was slightly off of the first group we shot and unfortunately, when we performed the 20 MOA measurement test the base had worked loose again and we did not catch it until later, so we are not sure on the accuracy of the clicks beyond what we saw in the box test. The optics performed well and there were no issues with clarity or contrast, the glass quality appears to be pretty good for a lower priced scope.

So now it was time to try out the ART system and see how it did. The concept of the system is actually pretty good and it was used effectively on the M21 back in the Vietnam conflict. It is quick, easy, and somewhat effective. The same concept applies here and it does an okay job of getting fairly close. The first step is to zero the rifle at 250 meters (everything is in meters with the Leatherwood), which is done with the scope set at 2.5x. This is enough magnification to get the zero dialed in, though do not expect any earth shattering group sizes. Once the zero is establish then you can use the charts in the back of the scope manual to get a cam value for your specific load, or find a value that is close to your ballistics. Since there was one specifically listed for the Federal Gold Medal Match 168gr load, we decided to try that ammo out. Once you have the cam value selected, you loosen some screws and slip the cam to that provided value, which was 420 in this case, and then tighten everything back up on the cam. Unfortunately, the values were considerably off; especially the further out you went, upward of 10 MOA at 1000 meters. Leatherwood does offer the suggestion of picking a mid-point and dialing in that range on the cam and then shooting a group, and adjusting the cam to match. This does help getting it closer through the some of the different ranges, but it is still off by a good amount. After fiddling around the best setting we were able to come up with was around 470, but your results will probably be different.


After the shooting evaluation we took some time on some ballistics software and started playing with numbers to see how the numbers might match up better and it seems that the cam on the ART system is geared more toward lower BC bullets than we use in the sniping field. When one dials the ballistic coefficient down to about .35, the numbers start to line up much better and this would make sense for hunting bullets. But with the high BC long range match bullets that snipers use, it seems to not fit well in the ballistic arcs that the ART cam is setup for.

This review was almost two separate reviews, one for the Hi-Lux scope, and the other for the Leatherwood ART system. While they come from the same company they are two distinct parts. The Hi-Lux scope was about normal when compared to other Chinese built scopes with the quality of the mechanicals coming into question, though the glass does appear to be good quality for the price. The ART mounting system itself is still a good concept for combat style long range shooting where quick target engagements may happen, but this ART implementation seems to be out of its element with sniping engagements and seems like it may work better for hunting bullets and rifles. We do not feel that in its current configuration that it would work well on a sniping rifle, though with a change to a higher quality scope and a different cam in the ART system it could work well. One distinct advantage the old original ART system from the M21 had was that it was only employed using M118 ammunition and it was tailored specifically for that round which allowed it to be setup more precise for the cartridge. If that were the case here, it could be made to work well enough for active deployment. The price would go up on both the scope and the mount as quality was increased, but you typically get what you pay for and ultimately it would be a better system for sniping than it is currently.

Sniper Central – 2012




You can not leave the 20 MOA rail on and use the cam as specified. It is built to us 0 MOA rail.

Richard Carter

the xm 21 issued to me had some draw backs like range and the scope but under the conditions I used it . at 500 yds it was consistent and my targets went down . at longer ranges it was more of a wild ass guess then brain work. but then the Utah match rounds we received improved both range and accuracy in the later part of 1969.


In Viet Nam I used a XM-21 sniper rifle with a Redfield 3 by 9 variable ART scope. For the whole system to work right, the shooter, rifle, scope and ammo had to all come together to form the sniper system. That meant when I went through Sniper School at An Khe I became one with my rifle and the gear assigned to it.

I loved my rifle and scope. They kept me alive for the last 7 months I was in Viet Nam with the 173D Airborne Brigade. During that time, I even engaged in one sniper versus sniper shootout and won it. The other/enemy sniper had about zero chance because I had the better gear and training.

I hated to leave my rifle and scope behind but there was no option. When I rotated home I gave it to a guy who I knew would use it all to their best advantage. I talked to him many years later and he also got a couple of kills with the sniper gear too.

The ART scope is a great system for a scope if you practice with it and get to know it well. It takes time but it is worth the effort if you plan to do lots of shooting. One thing: To make the scope really work to your advantage you MUST use high quality ammo and a high quality rifle. All 3 items then have to be zeroed to the shooter’s eyesight. Don’t think that you can use an ART scope with a cheap bolt action rifle, cheap ammo and get fantastic results because that will NOT happen. Go good stuff or go home.


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