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AI Skins Review: AICS ViperSkins

A few weeks ago I wrote the AI Stock Shootout, which compared the different AI stock configurations available.  One of the products I mentioned that showed a lot of promise was Victor Company’s ViperSkins, so I thought a good follow-up would be a more in-depth review on that product.

What are ViperSkins?

The Accuracy International Chassis System (AICS) is different than most stocks.  The body of most stocks like McMillan, H.S. Precision, and others are solid with some type of metal pillars or bedding block permanently embedded within them.  The body of the stock also provides part of the structural rigidity needed for precise repeatability.  The AICS on the other hand is a true chassis system, which has an internal framework that provides 100% of the support and the “skins” of the rifle are just plastic covers around the chassis.  ViperSkins are replacement skins / stock sides for the AICS, AE, or AW.

AICS 2.0 Bare Chassis with Victor Company's ViperSkins

The basic AI thumbhole stock hasn’t changed much since the original prototypes in the early 1980’s.  After a lot of customer feedback, Accuracy International recently release a new stock design they call the AX stock and it includes many modern and ergonomic features customers were requesting.  However, that doesn’t help the thousands of people that own the AICS.  That’s were Victor Company comes in with ViperSkins.  Essentially for $150 you purchase ViperSkins and bring that blocky, thumbhole AICS stock into the 21st century.  The kit replaces virtually every part of the stock you touch, so it can completely change the look and feel of your rifle.  You can see in the image below, ViperSkins combines the best parts of both the AICS and new AX design … plus a few other advantages I’ll highlight in this article.

AICS vs AX vs AICS with ViperSkins Side By Side Comparison

The Differences

The first thing you will notice is the finish of the entire stock body has more texture than the standard AI skins, which makes it feel slightly more “grippy” and less like slick, cheap plastic.  The fit and finish of the installed ViperSkins are every bit as good as the factory skins, which honestly was a little surprising.  There is absolutely no overhang, gaps, or play in any of the parts.


You’ll notice the back-end of the ViperSkins look almost identical to the new AX design.  The new big L-shape of the butt gives you something to grab onto to pull the rifle into your shoulder or maneuver the rifle to get in line with a target.  It just makes it feel like you have better control of the rifle.


One of my personal favorite features may seem small, but it can totally change how you grip the rifle.  The old-school thumbhole stock requires you to wrap your thumb all the way around the grip.  The ViperSkins provide a small indent just above the grip that acts as a thumb shelf.  That small thumb shelf allows you to now float your thumb on the bolt-side of the rifle instead of doing the full wraparound.  This not only feels more comfortable and natural for many shooters (especially those of us use to McMillan stocks), but can also potentially increase your speed when cycling the weapon.  You can still continue to use the full wraparound pistol grip if you prefer … the thumb shelf just gives you more options.  The thumb shelf indent is on both sides to accommodate lefties, and is also located so the safety on most actions is within reach.  This is one of the first things some shooters notice when they get behind the gun, and it is a small feature that opens up a new option for your grip.

Thumb Shelf on Victor Company ViperSkins

The new AX stock has a lot of new features, including a 13” barrel shroud that allows you to attach night optics equipment, illuminators or other devices to a rail on the forearm.  While that does sound cool, do you really need that?  I assume that was added to meet the requirements for the United States PSR contract bid, which seems to have been the catalyst behind this new series.  If you are like 95% of shooters out there and don’t plan to attach night vision in front of your scope anytime soon, the rail simply gets in the way and limits how low you can mount your scope.  Many shooters believe the lower you are, the more stable you are and that applies to the scope mount as well.  The lower the better.  You can see in the photos below there are virtually identical setups on an AX and AICS, and both are equipped with the Spuhr mount that will allow the lowest possible mount.  Ultimately the AX required a mount that was 0.32” taller (from the centerline of the bore) than the AICS, and that is a direct effect of the barrel shroud.  So although that fore-end rail looks pretty cool and seems like a  good idea … in practical shooting it may have more drawbacks than benefits.


The new skins overall are less blocky than the standard AI skins, and this is most noticeable in the forearm. Overall the edges are slightly more rounded and ergonomic than the original AI design.  For example, you can also see in the picture below indents above the mag well, which can provide a better grip.  Small features like this and the others mentioned make it obvious that there was just a lot of thought put into the ergonomics of this design.

ViperSkin-Less-Blocky-In-Forearm ViperSkins-Provide-More-Rounded-And-Ergonomic-Forearm

Another feature from the AX design that’s been integrated into the ViperSkins is the back of the grip is made out of a soft rubber material.  This provides a little more comfortable grip.

Weight Difference

Another benefit of the ViperSkins over the original AI skins is they are 4 ounces lighter.  However, in late 2012 Accuracy International redesigned their standard skins and dropped some of the weight.  Now the ViperSkins are right in between the two, with the new AICS multi-piece skins being 4.4 ounces lighter (20% lighter).

Weights of Victor ViperSkins vs AICS Standard Thumbhole Skins

Installing New Skins on AICS

Installing the replacement stock-sides on the AICS is simple and can be done in less than 10 minutes with just a few common tools.  You can watch the video below to see how easy it is.

The only thing tricky is that unlike the AICS skins that use the same screws throughout, ViperSkins have 4 different size screws.  Don’t worry though, it’s obvious if you get it wrong and easy to correct … just something to keep in mind.  Each kit includes an assembly diagram like the one shown below, so you know which go where.

ViperSkin Assembly Instructions & Diagram

Colors Offered

One thing great about the ViperSkins is that they are offered in a variety of colors, including real Flat Dark Earth (not the orange/tan color AI tries to pass off as FDE).  There is also an “OD Fleck Camo” finish that has darker flecks molded in that remind me of McMillan’s marble stock.  That variation should help it more naturally blend in to the surroundings.


Other Cool Upgrades from Victor Company

ViperSkins are just one of the cool upgrades produced by Victor Company.  They have a few others that are worth checking out.  Here are my favorites.

The Grippy Cheekrest is one of those things that I thought “Do I really need to upgrade that?”  The answer is YES!  The standard AI cheekrest gets slick on hot days when your sweating, but the cheek weld the grippy cheekrest provides is solid regardless of the conditions.  It has a type of rubber overmolding that is similar to the grips on some pistols, and something you’ll learn to appreciate the first time you use it.

Grippy Cheekrest & AI Cheekrest

The ViperSkins provide some screw holes in the forearm to allow you to attach accessories like a picatinny rail.  That can be helpful for a lot of modular accessories like flashlights, but can also be combined with a replacement part in the butt of the stock to allow for flush-cup Quick Detach (QD) sling attachments.  Those are becoming more standard, and this makes it easy to swap slings between rifles and get it on/off very quickly when needed.

Victor Company QD Sling Mount


Viperskins provide a very affordable way to increase the ergonomics of your AICS stock and incorporate modern features without having to break the bank to switch to an AX stock.  In fact, ViperSkins may offer a few additional benefits that some shooters will appreciate even over the AX stock.  I love it when someone like Victor sees an opportunity in the market like this and executes on a great idea.  It’s rare … but when it happens, we all win.

To learn more or to order some for yourself, visit: http://www.victorcompanyusa.com/viperskins.html

About Cal

Cal Zant is the shooter/author behind PrecisionRifleBlog.com. Cal is a life-long learner, and loves to help others get into this sport he's so passionate about. His engineering background, unique data-driven approach, and ability to present technical and complex information in a unbiased and straight-forward fashion has quickly caught the attention of the industry. For more info on Cal, check out PrecisionRifleBlog.com/About.

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