Itís no secret that Vortexís line of Viper PST rifle scopes caused quite the stir when they hit the market several years ago. Even today, a good five years later, they are still in such high demand that Vortex canít make them fast enough to keep up. It was just dumb luck that I happened to stumble across this unit while at one of my local gun shops.
The Viper PST Series is packed full of features. The lenses are XD (ultra-low dispersion) and are fully multi-coated using Vortexís proprietary XR lens coatings, and the exterior lens surfaces are ArmorTec coated to prevent scratching. The Precision-Glide erector system features their Precision-Force spring system to ensure precise and repeatable adjustments each and every time.
The EBR-2C MOA reticle is an etched glass unit that is mounted in the first focal plane (FFP) on this particular model. This ensures that no matter what magnification setting you are using the spacing of the sub tensions in the reticle will always be the same unlike with scopes with the reticle mounted in the second focal plane (SFP). This is advantageous when using the reticle for ranging, and it eliminates a possible variable that you could forget about or get wrong in the field.
The reticle features stadia lines spaced every two (2) minutes-of-angle (MOA) out to 24 MOA on all four posts of the reticle. From there stadia lines are spaced 0.5 MOA apart out to 36 MOA on the upper and two horizontal posts, while the lower post continues at 2 MOA increments out to 36 MOA. There are also dots extending out to either side of the lower post to be used for windage hold-off. The larger dots are spaced every 4 MOA and the smaller dots are spaced every 1 MOA. The stadia lines are also numbered (every 4th on the verticle and every 8th on the horizontal) to make finding the exact line you need faster and easier.
The Viper PST reticle is also illuminated in red. Vortex addressed one of my biggest gripes with illuminated reticles by putting an off position between each intensity setting on the illumination dial. This way no matter what intensity setting you prefer to use or the conditions dictate you only have to turn it one click in either direction to turn it off and back on again. Why hadnít anyone thought to do this before? The system uses a standard CR2032 battery which is very common and easy to locate a replacement when needed, and they generally seem to last a good long while if you remember to turn the unit off.
The main tube is a one-piece unit made of aircraft grade aluminum measuring 30mm in diameter. O-ring seals, Argon gas purging and rigid construction assure that the Viper PSTís are waterproof, fogproof and shockproof.
The Ocular bell features a fast-focus eye piece to adjust the focus of the reticle as well as the magnification dial which features Vortexís MagView fiber optic indicator.
The elevation and windage turrets are of the tactical style with both tactile detents and audible clicks for each click of adjustment. The elevation turret features Vortexes Radius Bar fiber optic indicator and their CRS Zero Stop mechanism to make finding your preset zero rotation much easier after a day of dialing up and down in the field. A side-focus knob is also found on the left side of the turret housing with marking ranging from 50 yards to infinity.
The exterior of the scope is hard anodized in a matte black finish, and a 4Ē sun shade is included in the box. The MSRP for this particular model is $1,049.00, and like all Vortex optics it is covered by their ďNo questions askedĒ V.I.P. unlimited lifetime warranty.
For testing purposes I mounted the Viper PST atop my custom Savage chambered in .22-250 Ackley Improved using a Ken Farrell zero MOA base and Burris Signature Zee 30mm rings. My pet load for this rifle consists of an 80-grain Nosler Custom Competition bullet being propelled to a muzzle velocity of just over 3,300 fps by a hefty charge of Hodgdon H4350 powder.
Once sighted in at the range I reset the turrets, installed the shims for the CRS Zero Stop, and proceeded to performed a six MOA box test at 200 yards to verify the accuracy of the tracking system. The Viper PST did not disappoint and provided a nearly perfect symmetrical box and when returned to its original zero stacked another three-shot group right on top of the first one. The clicks are very positive in feel and are accompanied by an audible click as well. I would conclude that the slight deviation in the box (1/4 MOA) was shooter induced than an inaccuracy in the tracking system.
Checking the depth of field on the Viper PTS was next on the list, and I again used the 200 yard range as its well suited for this particular evaluation. Fortunately the range hadnít been mowed recently so the plethora of dandelions made discerning the depth of field fairly simple. Adjusting the parallax for the clearest image of the 4x4 post used for the target stand, the depth of field seemed to be roughly around 4-6 feet.
The Viper PST also proved to have very good contrast and resolution. While I did utilize a USAF 1951 style resolution test chart from Vortex, I find that real-world testing yields more useful results that are more easily understood for the average shooter. As such I prefer to use a large pile of logs and limbs to evaluate contrast and resolution. The smaller the branches and twigs that I can make out that retain their crisp edges the better, and the more detail I can make out on the smaller branches and twigs the better. The Viper PST did very well and even bested what to this point had been the reference standard in my arsenal, a Bushnell Elite 6500 2.5-16x42mm. Part of that may be attributed to the Viper PSTís slightly larger objective diameter (50mm v. 42mm) as all else being equal a larger objective will always deliver better resolution.
To check for chromatic aberration (CA) I used a homemade version of Carson Opticalís Chromatic Aberration Test Chart which consists of a series of red and blue strips of decreasing thickness that will merge and appear purple when there is CA present. The thickest set of lines on the chart (#18) measure 1/2-inch wide, while the thinnest (#2) are 1/16-inch wide. The chart was setup at a distance of 30 yards and the Viper PST and two comparison scopes were all set at 12x magnification with the parallax adjusted accordingly for the distance. The smallest line the Viper PST could differentiate the two colors was #4 (1/8"), while both the Bushnell Elite 6500 2.5-16x42mm and Viper 6.5-20x44mm bowed out at #6 (3/16").
The last two items on my checklist were image distortion and field curvature (aka flatness of field). The Viper PST exhibited no noticeable occurrence of either when tested at 8x, 12x and 24x magnification on a variety of surfaces and objects with straight-line patterns.
Generally Iím not a big fan of illuminated reticles as itís just one more big knob hanging off the scope to catch on something when you have it slung over your shoulder working your way through the brush. Aside from making sure the battery had juice and checking the available illumination range I havenít used it, but as I mentioned earlier I really like that Vortex thought to put an off position between each illumination setting. The only thing missing is an automatic power-saving feature like the one found on Leupoldís VX-R series of illuminated scopes.
Not surprising the Viper PST did quite well in all of the optical tests and left me very impressed. At this price point it definitely should and its performance justifies the upper mid-level price that it carries. As good as the Viper PST is there are a still a couple small things I found to nit-pick.
First up is the magnification ring. Not only is it extremely stiff and almost necessitates the purchase of one of Vortexís Switchview Throw Levers, but it also only has a few magnification levels marked on it (6, 8, 12 and 24x). I understand that having a FFP reticle lessens the need for more precise markings for ranging purposes, but it would be nice to know exactly where Iím at in terms of magnification as 12 to 24x is a very large gap. If there were an indicator for 16 or 18x Iíd be a lot happier.
My second nit-pick isnít a big deal, but rather something I thought was worth mentioning for those who havenít ever used a FFP reticle before. Once you dial up the magnification past roughly 16-power (Iím guessing here due to the lack of markings as mentioned above) you start losing the lower portion of the reticle as it goes out of view. At full 24-power, the 22 MOA mark is the last stadia line visible through the scope even though the lower leg of the reticle has stadia lines clear down to 36 MOA. Now granted, if one needed to accommodate for that much drop they would dial all or some of it in on the turret to keep their aiming point as close to the center of the picture as possible, but in the heat of the moment in the field you donít always have time to dial in your dope and thatís where the stadia lines really become beneficial.
Last but not least, it wouldnít hurt if Vortex would include a few more shims in the package for the CRS Zero Stop as I could probably fit two or three more in to lessen the number of clicks the turret will go past zero when dialing back down. Iím running a zero MOA base, so if youíre running a 20 MOA tapered base there will be more than enough in the packaging for your needs. This particular rifle just shoots flat enough that I really donít need a 20 MOA base as my drop @ 1,000 yards from a 200 yard zero is just under 24 minutes.
Aside from those three very minor things Iíve been extremely impressed by the Vortex Viper PST. I particularly like the reticle and the fact that for most of my varmint hunting needs I will never have to adjust the turret off my 200 yard zero, but itís nice to know thereís plenty of adjustment range should I ever find myself in a need to dispatch a critter beyond 600 yards. The CRS Zero Stop and excellent turrets will be great for those looking for a 600 and 1,000 yard competition scope. I also have to tip my hat to Vortex for offering the Viper PST in both MOA and MIL configurations giving the customer to choose whichever he/she prefers.
While the Vortex Viper PST 6-24x50mm FFP isnít cheap at around $,1,000 on the street, itís still a major bargain in my option compared to some other options out there. Given all of the features and the stellar optical performance the PST offers youíd be hard pressed to find a comparable scope for the same money.
2120 West Greenview Drive
Middleton, Wisconsin 53562
2120 West Greenview Drive
Middleton, Wisconsin 53562