Posts Tagged ‘gas guns’
by Tom Gaylord, a.k.a. B.B. Pelletier
This report covers:
• The spring-piston powerplant
• How an AEG works
• Upgrading an AEG
• The problems with upgrading
• How to upgrade safely
When we last looked at airsoft upgrades, we talked about how the tuner has to look at the gun as a system. Improving one part of the gun without regard to the others usually won’t make much of a difference. In some cases, it may even make the gun prone to fail much faster. I told you about barrels and gearboxes last time. Today, we’ll look at the powerplant, itself.
The powerplants of spring-powered airsoft guns are identical to the powerplants of spring-powered pellet guns. They have a piston, a mainspring and a compression chamber. The piston has a seal that’s most often just an o-ring. That’s no different than the BSA Meteor Mark IV I’ve been reviewing for you.
The big difference is that airsoft powerplant parts are most often made of tough plastic instead of metal. And the coiled steel mainsprings found in airsoft guns are wimpy compared to the springs found in pellet guns.
Here’s an AEG airsoft piston with its mainspring. Note that this piston is made of nylon. Also note the piston’s final gear tooth is made of steel.
Compare a stock AEG mainspring (bottom) to an upgraded spring (middle) to a middleweight pellet rifle mainspring (top). Airsoft powerplants are weak, compared to pellet gun powerplants.
But they work! And they can be upgraded. You can install a heavier mainspring and a piston that fits the compression chamber tighter. These will boost your muzzle velocity. With some upgrades, it’s possible to boost the output so high that you have to use a heavier airsoft BB (plastic ball) to keep the gun shooting accurately.
We overlook what too much power does to our pellet guns, but it’s hard to ignore it when all your airsoft BBs are curving hard to the left, no matter how much you adjust the Hop Up! They go so slow and are so visible that you pay attention to them — like tracers in the nighttime sky — especially when you’re shooting a stream of shots on full-auto. So, you switch to the heavier BBs and find they’re even more accurate in that tight barrel you just installed.
My point is this — you upgraded your guns to get more velocity, but when you got it you lost accuracy. You had to switch to heavier ammunition to do what? Lower the velocity, again! Is that crazy or what?
Upgrading an AEG
While any type of airsoft powerplant can be upgraded, the most common type by far that people upgrade is the automatic electronic gun, or AEG. An AEG is a spring-piston gun that has a small high-torque motor to cock the piston. Because it’s electronic, a switch can be turned to make the motor operate just one time with every pull of the trigger — giving you semiautomatic fire — or to keep cocking and releasing the piston as long as the trigger is held down, which gives full-auto fire.
Unlike a firearm, the gun is not powered by the ammunition. It runs on electricity that powers a motor. As long as there’s juice in the battery, the action will cycle without regard to the presence of ammunition.
How an AEG works
The AEG has a large gear wheel that meshes with the piston. As the gear wheel turns, it draws the piston back until it reaches the spot on the wheel where there are no gear teeth. The wheel keeps turning; but when the teeth no longer hold the piston, the mainspring pushes it forward, firing the gun. The wheel continues to turn to the point that the gear teeth re-engage the teeth on the piston’s gear rack once again. The cycle repeats itself.
The AEG cocking gear is about to engage the first tooth on the piston gear rack. (Next photo shows this in detail)
The first tooth on the cocking gear is about to mesh with the first tooth on the nylon piston.
Here the gear wheel has rotated through all its teeth. The last gear tooth on the cocking gear has engaged the final steel tooth on the nylon piston. The cocking gear continues to rotate, and the piston will clear the gear teeth and be pushed forward.
Now the piston has fired and the gear wheel has rotated to the starting engagement position again. This keeps on going as long as the trigger is held down when the gun is in the full-auto mode.
For semiautomatic fire, the gear wheel turns only to the point of releasing the piston one time. It will rotate round to re-engage the piston gear teeth but not rotate farther until the trigger is pulled again.
If you install a stronger mainspring and better piston and compression chamber in your M4 AEG, that wimpy 8.4-volt battery that came with the gun will probably not run it too well. The gun that used to fire 700 shots per minute now struggles to put 400 out in the same timeframe, and everything sounds over-stressed — which it is. You need a stronger motor to power that new setup and a stronger battery to run it. And, while you’re at it, better get a battery with a higher mAH (milliampere-hour) rating. That way your gun won’t run out of juice after just the first magazine.
But you don’t just get a bigger battery. Sometimes, there’s no room inside the gun to house a bigger battery, and other times the bigger battery will take too long to charge when it runs down. Perhaps, it’s also time to change battery technologies from NiCad to lithium-ion (Li-ion or LIB).
Upgrading the batteries and motor
I did a two-part article on airsoft batteries for Pyramyd Air back in 2008 and 2009. Here are the links: Battery basics –Part 1 and Battery basics — Part 2. Those articles were well-researched, and the information still holds true today. Maybe there have been some technical improvements, but batteries are still batteries.
I think you need to understand why you want a better battery. Sure, it’s for more power and so you can operate longer and recharge faster, but the battery does nothing by itself. It powers the motor that drives the powerplant. If you’re not upgrading that as well, you gain very little by just swapping batteries. Maybe you just get the gun to operate as well as you thought it would when you bought it.
It turns back on itself
So, you upgrade the motor, battery, compression chamber, piston and mainspring. Let’s say you even changed the gears from nylon to metal. Bully for you! However, as you shoot your new, more powerful gun, you notice the cyclic rate starts slowing down, again, after the first few thousand shots. This is exasperating because you’ve now doubled the cost of the gun by adding all these upgrades — not to mention hours of your time spent installing them and getting them to run right.
You tear down the gun, again, and discover that the holes in the metal gearbox that serve as anchors for the pins that the new steel gears run on are all enlarged. They’re no longer round but are becoming oval. The pins have loosened! That’s because either the gearbox itself (the housing that holds the gears) is too soft to take the strain of the upgrades you’ve installed, or you didn’t shim each new gear properly — and they’re slipping sideways as they operate. This puts undue strain on their axels (the pins). You have to figure out what it is and then either buy a replacement gearbox, or buy an upgraded gearbox (if one exists) or, most expensive of all, drill out all the pin holes in the existing gearbox and install steel bushings for the pins to rest in.
Is it really that bad?
Is upgrading an AEG airsoft gun really fraught with all these pitfalls? Not usually. If you proceed with caution and learn as you go, none of these things ever needs to happen, or maybe one will happen and you’ll be able to deal with it. The guy who suffers them all at the same time is the guy who just throws money at his gun without bothering to understand how it works in the first place.
How to proceed?
How should you proceed if you really want to upgrade your gun? Well, first I think you need to have a reasonable expectation of what can be done to the gun and why you want to do that. I remember watching an upgrade to a bolt-action sniper rifle a number of years ago. The owner wanted the absolute best of everything, so he went for the tightest barrel, the best piston and compression chamber and the strongest mainspring. Then, when he cocked his newly upgraded rifle for the first time, it suddenly dawned on him that the bolt that used to take 20 lbs. of effort to cock now took almost 40 lbs.! That gun was the baddest beast around, only nobody could cock it! Try cocking a bolt-action rifle that takes 39 lbs. of force some time if you don’t believe me.
Had this guy bothered to first research his project, he would have found this out before investing all that time and money. What he wanted was a bragging-rights sniper rifle with no thought of how to actually use the gun. How do you brag about a gun that nobody can cock? A good sniper rifle is accurate and not that difficult to cock. You don’t do it all with a heavier mainspring!
Allow me to make a comparison in the automotive world. You can buy a nice used Acura Integra and drive it daily, or you can lose your mind and mod the engine up to 1,000 horsepower. At that point (actually, long before you get to that point), the Integra is no longer suited for making runs to the mall. It’s sole purpose is to travel 1/4 mile in the least amount of time.
You can build an airsoft gun that launches 0.28-gram BBs at 550 f.p.s., if you want to. Just don’t expect to use it for anything beyond wowing your buddies at the chronograph. You left the real world of airsoft some time back.
A safer way to proceed would be to use kits that manufacturers put together for specific purposes. Read what users of these kits say about them before taking the plunge. Maybe, if the upgraded barrel you selected wasn’t so tight, you might get by with a lower-powered mainspring that was still an upgrade over your factory gun.
And maybe stop and take a moment to ask yourself why you feel the need to upgrade your gun at all. All airsoft guns do not need to be upgraded — just as all pellet guns do not need to be tuned right out of the box.
Another safe thing you can do is to upgrade a battery by one increment of voltage. It’s usually safe to go from an 8.4-volt battery to a 9.6-volt battery — especially if the gun you’re upgrading comes with metal gears. And you can upgrade the amount of battery storage capacity (mAH) without suffering anything except a possible space issue. A battery with a higher mAH rating is usually larger. On some guns like the M4s with the extendable stocks the batteries have to fit inside the forearm, so make sure there’s ample room before you buy the larger battery.
I could go on and on with this and that tweak, but I think you get the idea. Know what you hope to achieve before you break the bank trying for that last f.p.s.
by Tom Gaylord, a.k.a. B.B. Pelletier
This report covers:
• Learning to work on airsoft guns
• Components of airsoft guns
• Parts commonality — the airsoft way
• Various upgrades to components
• Need for a systematic approach to upgrades
This report is the beginning of the second installment of a promise I made to some of our readers. They wanted to know how to upgrade and work on airsoft guns, and I said I’d show them. The last report was written half a year ago, but I’ll get the next one out a bit faster. In fact, I’ve already written it!
How do you learn?
If you think there’s a lack of information about working on pellet guns and BB guns — you should experience airsoft! Not only is there very little information, much of it suffers from poor translation from various Asian languages to English. If you persevere, though, there are places to find this information — and, today, you can add this blog to the list.
I had to learn the hard way — on my own by doing it. I think that’s a rite of passage among airsofters. Most of this work is not that difficult once you know what you’re doing, but there are so few places that tell you how to begin. I was fortunate to have an airsoft store owner advise me when I first learned, so I’ll pass along a lot of what he taught me.
Airsoft parts groups
The first thing to learn is that there are several components in any airsoft gun that can be upgraded. They are:
• Powerplant (usually sold as a kit but sometimes can be purchased separately)
• Batteries and motors — applies only to automatic electronic guns (AEGs)
• Accessory components (these are not what you’d think)
A universal truth
There are many airsoft guns and many airsoft manufacturers, but there is a very high degree of commonality throughout the industry. If we were talking about cars, it would be the equivalent of Ford making all the engines for all cars, regardless of what name was on the car. There would be no such thing as a Corvette engine. It would be a Ford engine with the Corvette name on the outside.
A small assortment of airsoft parts. These parts are available from online sources to upgrade most guns.
While there are dozens of different models of sniper rifles, there might be only 2 or possibly 3 really different designs. In some cases, there’s just 1. I’m not just talking about sniper rifles now — I’m talking about all the different families of airsoft guns. You look at M4s, for instance, and you’ll find 15 different names on the outside. That doesn’t mean anything. There might just be 2 different M4s that everybody makes into their own proprietary rifle. So, in the world of airsoft, there’s no such thing as an Armalite M4. The Armalite M4 is the same as the Olympic Arms M4 and the Colt M4, etc. Get it?
Unlike most airgun manufacturers, airsoft manufacturers freely publish their illustrated parts breakdowns and schematics like this. They’re protected from American liability laws by their U.S. distributors.
The first thing you have to do, therefore, is discover which parts will fit on your specific model. Don’t expect to find a universal Rosetta Stone with all this information! It’s not the same as going to the auto parts store and looking in that thick book of parts applications. What you have to do is converse with the manufacturer/distributor or go on the airsoft forums and ask questions. Let me give you a specific example.
Sniper rifle barrels are nothing but smooth tubes. If you paid $99 for your sniper “rifle,” the tube that came on it is probably quite a bit larger than most 6mm airsoft ammunition. Why? Because the sniper rifle manufacturer knows you are a cheap person — having spent only $99 to buy a sniper rifle, when you could easily have spent 3 times that amount. Because you are cheap, you will probably also buy and use cheap airsoft ammo, and that’s the stuff that is oversized and not uniform. It will work much better in an oversized barrel — where the term “work” means continue to come out the end of the muzzle when the trigger’s pulled.
This is a typical airsoft barrel.
But…if you actually want to hit a man-sized target at 50 meters with the first shot, a cheap sniper rifle is not the gun to use. For that, you need a rifle with a tighter barrel (which is still a smooth tube), and you need to find and continue to use only the one correct round in your gun. In other words, you need to become what many will call an airsoft “snob.”
As surprising as it may sound, you can buy a tighter barrel for your cheap sniper rifle — often from the company that made the rifle! You see, they didn’t actually make that barrel. They bought it from 1 or 2 barrel makers who supply barrels to all of the airsoft community (the Ford engine in the Corvette). And there are different grades of tightness among barrels! This is where the airsoft forums come in handy. Someone will tell you that to upgrade your $99 Whango Tacticool M40, you need a Sho-Lin barrel that’s only 0.20mm larger than 6mm. It will work on your rifle, but you have to shoot 0.24-gram Black Mambas through it because everything else will jam.
If you can follow this advice to the letter, you can make a nice sniper rifle. And, when you’re done with the barrel and all the rest of the modifications, the price of your upgraded rifle will have about tripled! Small world, no? But, if you’re the guy who constantly wants to substitute Owl Sweat for Kangaroo Juice, because there’s a sale on it at a store near you, don’t even think of modding an airsoft gun! All you’ll do is spend money on a pile of parts that will never work together.
The Asians call this the Mech Box or Meca Box. It took me several months to figure that out the first time, and it’s important to know if you want to find them on the internet.
The $125 M4 AEG often comes with plastic gears. If you plan on shooting it only on holidays and at family gatherings, buy one and be done with it. By the way, if there’s a brand name like Colt on the outside of the gun, plan on spending 3 times as much and still getting plastic gears (sometimes)!
If you want to go into battle and have the gun continue to function for several days and thousands of shots, think about metal gears. But it doesn’t end there. There are also special shim spacers to keep the gear wheels aligned under a load, and there are special reinforced metal gearboxes that don’t wear like the cheaper gearboxes do. At the top of the list are the gearboxes that are built with pins (gear axels) that have been align-bored by a custom builder. A gearbox upgrade kit in a blister pack can cost you $68, or you can spend $400 with a custom builder who makes the gearbox specifically for your gun.
So, you see the Super Zombie Black Ops (a name I just made up) M4 AEG selling online for $99msays it comes with steel gears on the outside of the box! Big deal! That’s the airsoft equivalent of a pellet rifle manufacturer saying their rifle shoots at 1,400 f.p.s. In other words, although it sounds like it implies quality, what they don’t tell you is that those gears are not aligned properly and are set inside a cast pot metal gearbox.
Like everything else, in airsoft there are things that do work well and then there are the retailers who trade on the general ignorance of the buying public. They use buzzwords like metal gears to suck in the beginners. To mean something, the metal gears need to be run on pins of the correct size, have thrust washers to hold them in alignment and be inside a gearbox that can take the strain — and the whole reason for all of this is so you can get some benefit from that high-torque motor and uprated battery you also installed. If you aren’t going to do this in a systematic way, you might as well eat the metal gears, for all the good they’ll do by themselves.
I’ll stop here because this report is getting long. In the next installment, we’ll look at the airsoft powerplant, upgrades to batteries and motors, and the best way to get started working on airsoft guns.
by Tom Gaylord, a.k.a. B.B. Pelletier
I decided to write this for those readers who indicated they were interested in airsoft to some degree. I know this is an airgun blog, and that means pellet and BB guns — not airsoft, but there are some crossovers. For example, many airsoft companies are now entering the world of steel BB guns. I promise we’re not going to become half-and-half or even one-quarter airsoft; but since there are questions, I feel the need to address them.
History of airsoft
This will be short and sweet. Airsoft came about in the Orient in the 1970s, when the demand for realistic guns that were not firearms was first satisfied. The early designers made their guns shoot 6mm plastic balls that they have since come to call BBs.
The early guns were made to satisfy the needs of collectors to see, feel and even be able to disassemble the guns in which they were interested. So, the early thrust of airsoft guns was for collectors, only. However, the fact that the manufacturers made these guns fire their plastic BBs soon evolved into an entirely different interest. People began conducting wargames with the guns. Instead of paintball, which is very painful when the .68-caliber balls hit flesh, the 6mm plastic balls had almost no impact. Of course, the guns in those days were firing at very low velocities; because it was realism, rather than the gun’s ability to shoot, that attracted buyers.
Once the wargames began, airsoft split off into two directions. The collectors wanted highly realistic guns, and the wargamers wanted guns that were accurate at long distance and would hold up under simulated combat conditions. Some of the early collectible guns sold for thousands of dollars. Indeed, there are still a few of these collector guns being sold today. One example is a very real airsoft Browning Automatic Rifle (BAR) that sells for well over $3000. But the collector market has been far surpassed by the wargamers, who now call themselves skirmishers. Airsoft guns for skirmishes are the biggest sellers in today’s market, which has grown to more than a billion dollars in sales annually.
The BB gun wars
I’ve written several articles about the BB gun wars that were conducted in the United States from the 1890s until the 1960s. The BB gun wars were literally backyard battles fought by teams of kids with BB guns. Every community had them, and each bunch of kids had their own rules. I’ve owned several BB guns with multiple dents in both the wood and metal from the impacts of BBs that are obviously survivors of the BB gun wars.
It’s my contention that the BB gun wars still rage today, but they’re now being fought with airsoft guns. Apparently, there’s a need for people to shoot at each other in mock combat, and airsoft guns seem to fill this need.
Because shooting at people is so emotionally-charged, IPSC shooting has recently become popular. IPSC stands for the International Practical Shooting Confederation. It’s the international extension of practical pistol shooting that began as law enforcement training in the U.S. in the 1960s. IPSC competitors shoot from 30,000 to over 100,000 rounds each year in training and competition, so the game is not for poor people.
Airsoft guns are a wonderful way to get into this competition without spending the kind of money that it costs to shoot firearms. For one-hundredth the cost of firearms, shooters can have the same fun under safer conditions with 6mm airsoft guns.
Airsoft history is rapidly evolving. In just 40 years, it’s gone from pure collecting to wargames and now to practical pistol shooting. Who knows what’ll happen in the next 10 years? What’s obvious, however, is that the technology of the airsoft guns is evolving as fast as the interest is. This is a burgeoning area that’s spending a lot of money to satisfy multiple needs.
Let’s examine the airsoft powerplants so we can see what exists and what’s possible. The first powerplant we’ll look at is the spring-piston.
The spring-piston airsoft powerplant is no different than a spring-piston found in any other type of airgun. A piston is powered by a coiled steel spring and moves forward rapidly to compress a column of air that then drives the airsoft BB. Most airsoft spring-piston guns are repeaters, but they must be cocked for every shot. You sometimes see these repeaters called single-shots because the people writing about them don’t understand the difference between a true single-shot that only holds one round and a repeater that holds many round but must be cocked separately to fire each one.
Spring piston guns are among the least expensive, and yet they can also be very powerful and accurate. Sniper guns are powered by spring pistons for the most part. The lowest-powered spring-piston guns cost very little and are not built to last a long time. They have a lot of plastic parts that eventually do wear out. But if you don’t abuse them, most will give you many thousands of shots that will be surprisingly accurate.
Gas airsoft guns are very similar to gas airguns, except they do employ a wider range of gasses. Besides CO2, which they’ve begun to use in the last 15 years, airsoft guns also use other industrial gasses that go by colorful trade names. Green gas and red gas are 2 of these; and green gas is, by far, the most popular. Green gas is nothing more than propane, though some suppliers do infuse some oil into the gas to help lubricate the airsoft mechanisms.
Green gas runs at a nominal pressure of 115 psi. It’s supplied in dispensing cans that have nipples that couple with the inlet valves of the guns they serve.
Someone asked me if green gas was as powerful as CO2, which is pressurized to 850 psi and higher. Well, it isn’t. But that doesn’t mean very much, however, because CO2 has to be stepped way down to safely operate an airsoft gun. The same gun can use both green gas and CO2, it just needs two different magazines — each with its own valve to handle the correct gas.
Generally speaking, gas guns tend to be faster than spring-piston guns, but that isn’t always the case. There are bolt-action spring-piston sniper guns that are very powerful. It’s impossible to make a blanket generalization.
Automatic-electric guns (AEGs)
AEGs are spring-piston guns that are powered by small high-torque electric motors. The motor cocks the piston and trips the sear. The gun usually has a selector switch that allows full-auto (the motor repeatedly cocking and releasing the piston as long as the trigger is held down) and semiauto (firing one time per trigger pull). Besides the spring-piston side of this powerplant, there’s the electric side that deals with batteries, motors and gears.
AEGs are popular because they can shoot full-auto, which gamers and collectors both enjoy. They also are among the fastest-shooting airsoft guns, although bolt-action sniper guns can be modified to be very fast, as well. AEGs allow people to experience things that most people cannot experience with firearms; and, of course, they do it at a fraction of the cost. Even law enforcement agencies are using AEGs as training simulators because they’re much safer than firearms that shoot training ammunition called Simunitions. You can make a mistake with a firearm and kill someone — it happens all the time. But you can’t possibly load a firearm cartridge into an airsoft gun, no matter how realistic it may seem.
The technology is changing rapidly. Today, there are even a few hybrid AEGs that can be used with or without electrical power. Obviously, these will appeal to people who never want to be caught without a functional gun.
What comes next?
Next time, I’ll talk about modifying airsoft guns. Not all guns can be modified, but a surprising number can be; and the manufactures do supply the parts to make the modifications.
I’ll also talk about power, which is fast becoming an important topic. As the guns become more powerful, the “soft” in airsoft is being tested to the limits.