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For more information about the Evolution Autococker, in the U.S., contact:

Smart Parts
Mailing Address:
PO Box 3200
Latrobe, PA 15650-5000
Delivery Address:
Loyalhanna Business Complex
100 Station Street
Loyalhanna, PA 15661
Phone: 724-539-2660
Fax: 724-539-2298

Outside the U.S., contact the manufacturer Belsales

Ravi's Paintball Place

© Ravi Chopra, 1997

There are two major philosophies found in the designs of custom or "signature series" Autocockers. The first is the hot-rod approach. With the hod-rod approach, the airsmith goes all-out, changing anything and everything on the 'gun to squeeze every last ounce of performance out of the basic Autococker form. The usual result of this approach is a 'gun with an extremely short, lightweight trigger and hopped up components designed to make it easier to cycle the 'gun faster. These hot-rods usually sacrifice efficiency, reliability, and your warranty for a higher rate of fire. The second approach entails perfecting the stock 'gun without significantly diverging from the stock geometry, configuration, and components originally laid down by W'Orr Game Products.

The Evolution from Belsales Performance in the U.K. is a 'gun designed under the second philosophy: that Budd Orr knew what he was doing and that ultimate performance could be derived from tuning the stock configuration. This has had the unfortunate side-effect of giving the Evolution the reputation of being essentially stock in feel and performance, if not in appearance. What I'd always heard about the Evolution is that all you get for your $1000+ is an essentially stock Autococker with a reverse-cut block, pretty anodizing, and a Smart Parts barrel. It was with this not-terribly-flattering impression that I started my evaluation of the Evolution.

When I contacted Smart Parts about acquiring an Evolution for review, I was put in contact with Graham Easton; Smart Parts' major contact man with Belsales. As one of the people involved in the design of the Evolution, he was particularly well suited to inform me about the design and progression of the Evolution over the years since it was first conceived. Over the course of several conversations with him, I learned that the common conception of what goes into an Evolution Autococker could not be much further from the truth. Though Belsales does stick to the basic design philosophies laid down by Budd Orr, very little of the stock 'gun remains in the Evolution once it leaves the shop. In fact, as Keith Belsale of Belsales put it "We modify, or hand work, or replace with our own every part of the 'gun except for: sear spring, grips, safety clip, safety ball, safety spring, sear pin, air receiver, air receiver screw, semi-block, exhaust valve (we make it anyway), beavertail (we make it also)."

The Evolution sent to me was an "Ultimate Evolution Autococker with Gun Mounted Nitro" package. It included a black/red/silver splash anodized Evolution Autococker, a 14" Smart Parts Tear-Drop barrel anodized to match, and a Smart Parts bottom-line mounted Max-Flow nitrogen system with a 68 ci tank. The retail price of this package is $1575. I later purchased a '97 Evolution Minicocker in midnight-green splash with Belsales' new .45-frame, "Angry" 4-way valve, and Twister regulator external adjustment kit. I've included both my initial impressions with the Evolution Autococker and my long-term findings with my own latest-model '97 Evolution Minicocker.

In my review of the Evolution I've broken it down into systems: trigger, autococking system, internals, accessories & extras, cosmetics.


The trigger was the first, biggest surprise I experienced with the Evolution. With essentially stock dimensioning and parts, I was expecting the trigger to have a relatively stock-like feel; heavy, long, a bit rough. I was way off base.

The first thing I noticed about the feel of the Evolution's trigger is that it is extremely smooth. The Belsales airsmiths have managed to eliminate virtually all of the looseness and slack without incurring any binding or dragging. I can't stress strongly enough how impressive this is. Typically, the more slack you take out of a trigger's action, the more you force it to stay near the 'gun body and frame walls making it more likely to drag or rub. The Evolution manages to escape that trap, providing you with an exceptionally tight and smooth trigger action.

The most obvious modification is the relatively standard vertical guide screw to take up excess up-down slack at the front of the trigger plate. In late '97 and newer models, this guide-screw has a brass insert at it's tip for an even lower-friction contact with the trigger than the old steel guide. The rest of the trigger assembly appears to be relatively stock at first glance. What you can't see from the outside, though, is that all of the parts in each Evolution are custom made and hand-matched to fit perfectly and provide an exceptionally clean trigger pull. Smooth action also results from meticulous polishing of all the moving surfaces. The top of the trigger, back of the sear, trigger-sear interface, and bottom of the trigger are all mirror-polished. I've seen very few triggers that have had their parts as well polished as these.

The trigger feel is improved further with the new Belsales .45-style trigger frame which I had installed on my own Evolution Minicocker. Not only does the .45 frame fit the trigger and sear plates more closely, it also allows for a small upward bend in the back stem of the trigger plate that eliminates the very last vestige of vertical slack in the trigger (sadly, this modification does not work with the stock frame). It is difficult to get just right, but it is perfectly implemented by Belsales. The .45 frame is available separately for installation on any Autococker. It comes with the hole for the guide screw already drilled and tapped but curiously does not include the hole for a trigger-stop screw - a feature available on virtually every other .45 frame on the market.

In older Evolutions equipped with stock Budd Orr 4-ways, Belsales had to match components from several valves to provide the most perfect fit, smooth movement, and leak-free action. Over the last year, though, several airsmiths have expressed great frustration working with the stock 4-ways from W'Orr Game Products. Some of them have begun installing aftermarket 4-ways. Keith Belsale built his own. Newer Evolutions come with the new "Angry" 4-way valve (named after the emotion it is perdicted to elicit from Budd Orr). The valve is construted entirely of brass and is of one-piece construction (eliminating 2 end-plugs, 2 C-rings, and 2 C-clips from the stock valve's construction). The input and output stems are much closer together for a shorter switch-length. Naturally, the performance of the Angry is as good or better than that of the hand-matched valves on early 97 and older Evolutions. Like the .45 frame, it is also available separately.

The only thing that feels even remotely stock about the Evolution's trigger is the pull length which remains at 5mm due to the stock dimensioning of the trigger assembly. Even that is not onerous, though. The significantly smoothed action of the trigger and lighter springing allow the trigger to be pulled very quickly with minimal potential for short-stroking.

Speaking of springing, the Evolution's springs bear some mention. Much of the stiffness and roughness that appears in many Autocockers' trigger results from excess drag between the trigger and sear. Many people try to combat that by polishing the trigger components as already done in the Evolution. Belsales took it a step further through intelligent spring selection. They've set the 'gun up to work with a very short and soft sear-return spring and have installed an only slightly softer-than-stock trigger return spring. The advantage of this is that you get a soft return on the sear, minimizing friction at the trigger-sear interface, but you get a strong return on the trigger to ensure fast closing of the 3-way valve and reset for another cycle. Few custom shops put this much thought into the design of their products.

There is just one curious feature of the Evolution's trigger assembly. Apparently, Keith became tired of people messing up their Evolutions by replacing the stock 3-way actuator rod (timing rod) with a stainless steel rod and not properly retiming the paintgun. To combat this, he's begun putting stainless steel rods of his own on all current Evolution Autocockers. The rod is actually a bit larger in diameter than the stock rod so it fits the hole in the trigger a bit closer and keeps the rod more precisely in line with the 3-way to provide smoother action and fewer leaks. What's odd is that the rod is not threaded to screw into the 3-way coupler. Like the stock rod, it is still slip-fit and retained only with a small allen screw. What he either missed or ignored is the fact that the main reason people replace the stock timing rod with stainless aftermarket versions is because these replacement rods thread into the coupler. The advantage of a threaded rod is that if the retaining screw loosens, the rod can't just slip out and leave the shooter with a non-functioning 'gun. Sorry, Keith, but you missed the boat with this modification.

On the whole, the Evolution's trigger is amongst the smoothest I've felt, particularly when built into Belsales' own .45-frame. The pull is long compared to some other top Autocockers, but it is sprung and timed for a fast return and to minimize the chance of short stroking. This is not the fastest Autococker trigger in the world; hot-rod people looking for the softest, shortest, fastest trigger will not be happy with it. But it is fast enough for most and more reliable than taken-to-the-edge triggers. On one last note, make sure to put some paint through it before you judge the trigger of the Evolution. Dry-firing does not sufficiently convey just how good this trigger feels in game situations.

As a final note, I am a total hot-rod guy. I've never been happy with an Autococker's trigger until I've had a chance to tweak it to my own tastes, not even my own reference Autococker (which you can see and read about at my web page: ). The Evolution has the only 'cocker trigger I've ever felt that I did NOT immediately want to change. This is as strong a compliment as I can give.


The Autococking system is the system of components that pump the 'gun for you between shots. It includes the regulator, pneumatic cylinder (a.k.a. the "ram"), 4-way valve, and back-block. The Evolution Autococker has tuned stock versions of all of these components to bring it up to state-of-the-art performance levels.

The regulator is a polished and tuned version of the Sledgehammer, the same regulator that comes on the stock Autococker. It has been turned down by Belsales to feed the Autococking system only about 90 psi (the Sledge on a stock 'cocker comes set at 130-140 psi) since the Evolution is tuned to run at much lower pressures. This works perfectly well in 99% of all situations. Unfortunately, there are those strange situations in weather and temperature extremes where, for whatever reason, the Sledgehammer's output pressure drops to a point where it isn't quite enough to cycle the 'gun properly. To adjust the Sledgehammer, you have to disconnect the hose and disassemble the regulator to get at the adjustment nut. Though excellent externally adjustable regulators are available as aftermarket parts, Keith Belsale once again struck off on his own. The result is the Twister external adjustment kit for the Sledgehammer. This kit which replaces the Sledgehammer's front cap allows you to fine tune the Sledgehammer's output pressure with a simple twist of its knob. This option finally makes the Sledgehammer a serious competitor with Palmer's extremely popular Rock regulator. Once again, this kit is available not just for Evolutions, but for any Sledgehammer-equipped Autococker or Minicocker.

The ram has been polished for smoother, faster, more efficient action. Though I still feel that Clippard rams are a bit faster, these new WGP rams are certainly fast enough to keep up with any player's trigger finger, as well as being rebuildable in the case of a blown seal.

As I mentioned in the trigger section above, older Evolution 4-ways, though made from stock components contain matched and polished parts. Newer Evolutions come equipped with the new "Angry" 4-way. Like the trigger assembly, these are possibly the smoothest 3-ways I've ever felt. I'm rather surprised that they do not leak.

Finally, the Evolution Autococker has a lightweight reverse-cut "P-block", so named because of it's resemblance to the letter "P". The importance of including a lightweight block has been reduced by the new addition of cut blocks as stock equipment on all new Autocockers.


The internals of an Autococker are the components responsible for delivering high-pressure gas to the barrel behind the paintball. In the Evolution, these components have been specifically designed to allow the 'gun to operate at lower pressures. The degree of modification that they've gone to to achieve this is quite impressive.

First, they open up the chamber in front of the exhaust valve to twice the volume found in the stock 'gun. This allows for a large reservoir of ready gas to flow through the valve as opposed to other 'cockers which have to draw more gas from the gas supply when the 'gun is fired. This allows a reduction in operating pressure.

Futhermore, and very importantly for Minicockers such as the one I bought and tested, Belsales has significantly modified the front-block screw for improved air-flow. In the Autococker, this hollowed-out screw allows air entering the 'gun body from the vertical ASA to pass into and through the front block and to the Sledgehammer regulator on the front of the 'gun. In the Minicocker, the main gas supply actually feeds into the front block and must pass through this screw to reach the exhaust valve in the 'gun body to fire the paintball. The stock screw has only a very small channel through it, seriously restricting flow through it during rapid fire. Belsales has made their own front block screw with a much larger channel down its middle and a gigantic side-hole matched specifically to the front-block in which it is installed. This much freer flow through the front block also allows a reduction in operating pressure, particularly with the Minicocker.

With the exception of the exhaust valve, all parts of the valve have been modified or replaced with custom-built components for more consistent, lower pressure operation.

The hammer and velocity adjuster system installed in the Evolution is the very cool Rex kit. First, the system is built to take the larger diameter Nelson-style springs, and comes with two springs of different weights. Both of these springs are softer than the stock Autococker mainspring and therefore allow for lower pressure operation of the autococking system. The hammer is lighter than stock and is well polished. The sear lug is reversed and is accessible via a hole drilled through the top of the 'gun so it can be easily timed without removing the grip frame. The most impressive feature of the kit is the velocity adjuster. Velocity is adjusted by inserting an allen wrench through a hole in the block and into a "worm screw" to the left of the cocking rod. The worm screw engages the main velocity adjusting screw which moves in and out to increase or decrease tension on the hammer spring. Opposite of the way a stock 'cocker is adjusted, turning the screw counterclockwise increases velocity and clockwise decreases velocity. The coolest thing about this is that you never have to remove the cocking rod to adjust velocity. With this kit and an appropriately drilled block it becomes easier to adjust your 'cocker's velocity than it is to adjust a 'mag without a tournament cap! I liked this kit so much I installed one in my own reference tournament Autococker.

The final internal component is the Evolution Bolt. This is a very lightweight aluminum venturi bolt with some rather unique characteristics. First, it only has two o-rings; the ones flanking the air chamber which receives gas from the exhaust valve below it. There is no front o-ring to seal the bolt in the barrel. This gave me some concern at first since the point of the front o-ring is to stop gas from escaping around the front of the bolt and up the feed tube. This can lead to significant blow back, particularly in poorly timed 'guns. This turned out not to be an issue in the Evolution, though. The bolt was machined to fit relatively tightly and the 'gun is quite conservatively timed. I did not find any significant blow back in any of my tests. The air chamber in the bolt itself is quite large, larger than any I've seen in any other bolt. Six holes lead straight forward from the air chamber to the front of the bolt. When I asked him about this curious design, Graham Easton told me that they tested many different shapes and configurations for the bolt's air chamber and venturi porting and this design offered the best performance of the many they tested. It does make sense that it would be more gentle on the paintball since the six small holes will offer more resistance to air flow and slow the air more than a stock-face bolt and will apply the air somewhat more gradually.

In play, the effects of the low pressure system and venturi bolt are quite evident. This 'gun is very gentle on paint. Even very old and brittle paint shot through this 'gun without a problem. Velocity consistency was also top notch. With good paint and my Max-Flow nitrogen system I found very consistent ±3 fps velocity strings were the norm.

Over longer term use of my '97 Evolution Minicocker, I found some other surprizing characteristics. First, the 'gun's efficiency is extremely good. From my 69 ci, 3000 psi MaxFlow nitrogen system, I am getting on the order of 1000 good shots per tank. Additionally, I'd been running the 'gun at the recommended input pressure of 500 psi - lower than the stock Autococker requires but far from overwhelming when compared to the low-pressure systems currently so popular in Autockckers. Upon further testing, I found that the Evolution Minicocker shoots just as well and gets just as good a velocity at an input pressure of 290 psi! As it turns out, as input pressure increases Autocockers velocities climb only up to a point. Beyond that point, the extra pressure starts closing the valve faster and actually causes a drop in velocity as input pressure is increased. The result is that, for any valve and spring combination, there are two input pressures that will give you appropriate velocities (between the two pressures, your velocity is high). At 500 psi, I was at the higher of the two pressures. That the Evolution Mini with an essentially stock exhaust valve can give 300 fps velocities at 290 psi is extremely impressive.


As with any paintgun sold by Smart Parts, the U.S. distribution Evolution Autococker comes with a Smart Parts spiral-ported barrel. The Evolution Autococker came with a Tear-Drop Smart Parts barrel anodized to match the rest of the 'gun. The Tear-Drop differs from their top-of-the-line "All American" barrel in a couple of ways. First, it's a one-piece barrel with a single consistent I.D. the whole way down the barrel. Second, the spiral porting starts much further down the length of the barrel, extend over a shorter length, and increase in size as they approach the end of the barrel. Finally, the inside surface is anodized rather than coated with their "Smart Tuff" ceramic. This barrel offers some nice advantages over the All American. Though it's accuracy at extreme range may not be quite equal to the AA, it has a particular advantage in the case of a barrel break. In the All American, I've always found that when you get a break, the larger bore of the second stage of the barrel and the large holes tend to hang on to paint and cause all following balls to hook wildly until you squeegie the barrel. The Tear-Drop has a consistent bore size down it's full length so subsequent balls tend to clear the bulk of the paint out relatively effectively.

My '97 Evolution Minicocker came with a 16" match anodized All American barrel with the standard bore I.D.. Though I liked the barrel's performance, I felt it was a bit long for many situations in which I typically play. For that reason, I bought a 14" All American barrel set in 3 different I.D.'s. With this set, I've always been able to match the barrel I use to the size of paint I'm shooting that day. Despite my reservations about the difficulty of cleaning All American barrels, I have so few breaks in my Evolution that it has not become an issue.

All new spec. stock Autocockers now come with a Cooper-T ball-bearing style detent to prevent double feeding. While this is unquestionably a good addition to the stock 'gun, I do not believe that it is the best choice for a detent. For a variety of reasons I prefer the Pro-Team and wire-nubbin-style detents. Unfortunately, since all new 'guns come with the ball-bearing detent, you no longer have the option of having other detents installed. The Evolution is one of very few exceptions to that rule. The Evolution comes with a wire-nubbin style detent which has two advantages. First, it will not jam-up over time as the ball-bearing style detents can when they become choked with old paint and shell. Second, it does not scar the bolt like the ball-bearing which can take a good sized divot out of your bolt over many cycles.

The bolt has a unique retention system. Where the stock system has ball-bearings in the push-pin, the Evolution bolt has a large spring-loaded ball-bearing in its back which snaps into a groove in the push-pin. The pin pulls out easily with a quick jerk and there are no small ball bearings in the pin to go bad, break, or lose.

This Ultimate Evolution package comes with a bottom-line mounted Max Flow nitrogen system with a 68 ci tank. The positioning of the tank with it's current mounting system places it a little too high and a little too far back for my tastes. With a drop-forward or Versa-Cradle, it was positioned perfectly. I'll be reviewing the performance of this nitrogen system in an upcoming article. For now, I'll say that this is an excellent nitrogen system that does not need a second stage of regulation to achieve excellent velocity consistency.

To round out the package, the Evolution comes with a beavertail to make it tournament legal, and a set of VL grips to improve the feel and grip angle.

The Evolution Autococker was the first aftermarket Autococker to receive the official W'Orr Game Products stamp of approval. Apart from the comfort of knowing that the Evolution is of high enough quality and reliability, you also maintain the full 1 year W.G.P. warranty with Belsales covering their proprietary parts. U.S. customers should send their 'guns in to Smart Parts for all warranty work. Tinkerers beware: WGP, Smart Parts, and Belsales all consider the Evolution to be a complete 'gun. The only people they consider to be qualified to work on the Evolution are trained employees of those companies. Any other aftermarket work done to, or parts added to an Evolution invalidate its warranty.


The millwork is relatively spartan by today's standards; the bottom edge of the body is rounded off, the sight-rail is milled down in front, a reverse-cut "P-block" cuts into the back of the body, a few shallow cuts are made in the body, and the shroud is milled out in the middle and raised in front to match the sight rail. Though it is relatively simple, the millwork is extremely clean and quite handsome. In my opinion it strikes a nice balance of looking very good without being ostentatious. Additionally, the 'gun is meticulously polished. Virtually every other milled Autococker shows some swirls in the cuts that did not get polished out. Not the Evolution. Every cut is perfectly smooth and clean. This is unique in my experience.

The Evolution Autococker came with Smart Parts' "Crazy Black Splash" anodizing pattern. I ordered my Mini in Midnight-Green. You have to decide for yourself how much you like the color patterns that Smart Parts offers (I like them). What I can tell you is that Smart Parts' anodizing is, bar none, the best in the business. It is the most even, most lustrous, most perfect anodizing I've had the pleasure to set eyes on. There are no areas of pooling and no thin spots. The colors are deep and rich, almost like an enamel. The only disadvantage is that, like with the millwork, you don't have the option of customizing the 'gun to your tastes; you're stuck with what they offer.

Finally, the Evolution has all stainless steel rods. 'Nuff said.

When the Evolution first came on the scene, it was a pretty wild design. But today, when many Autocockers have wild millwork and splash anodizing it almost seems sedate. Never the less, the quality of the cosmetic work on this 'gun is second to none.


I'll make no bones about it. Even with the nitrogen system, at $1575 retail the Evolution Autococker is extremely expensive. Without the nitro system the price only drops to $1175. Though there are other custom Autocockers that cost even more, they offer the buyer much more choice as to what goes into them and how the finished product looks. Smart Parts and Belsales offer no apologies. They never claimed that the Evolution was the cheapest high-performance Autococker out there. They only assert that it is the best.

When I first spoke to Graham Easton about the Evolution, he said "I think you'll find it to be the finest Autococker available." I don't know if I can agree with that. Calling something the "finest" seems to imply that it's the best, and I don't think that there is a "best" Autococker anywhere. Different people have different tastes, and for some, the Evolution will not be appealing. On the other hand, I do feel comfortable saying that the Evolution is perhaps the most refined Autococker available. This 'gun has a look and feel of excellence about it. Every part fits perfectly, every moving part moves smoothly and precisely, every part of it's design is well thought out and executed.

I'll admit it. I am a total hot-rod guy when it comes to Autocockers. My own reference Bad Boyz Toyz Autococker is tricked out to the hilt and can be shot at an absurdly high rate with ease. None the less, I was extremely impressed with the Evolution. It is refined to the point of perfection, it is extremely reliable, its performance is exceptional, and it is very gentle with bad paint. I like my own Autococker better, but I've bought an Evolution Minicocker anyhow for the times when my top 'gun breaks down, breaks paint, or just doesn't make me happy. In fact, I've found that I shoot a bit more accurately with the Evolution in long-balling situations since I don't feel such an urge to shoot it fast.

So the real question is, is it worth the high price when you can get other high-performance Autocockers for much less? Obviously, for many the steep cost of entry will keep it from ever even being a consideration. But there are many players, pro and recreational alike, who do spend this much or more on their 'guns. If you have a yen for an Autococker and are considering 'guns in it's price range, you'd be doing yourself a great disservice by not at least considering the Evolution. It isn't the stock 'cocker it's been made out to be.

In conclusion, let me say that I HATE this article. I've built my reputation on honest and complete criticism. Looking back over this article, I find that I have little but good things to say about the Evolution Autococker. I've gone over it with a fine-toothed comb and the only serious criticisms I find I can make is that it's too damn expensive and it won't please people looking for the very lightest and fastest trigger.

All material at this site is © Ravi Chopra, 1999