1.1 What is airsoft all about?
1.2 So they are toy guns, right?
1.3 Are airsoft guns dangerous?
1.4 Isn't airsoft a bit militaristic?

2.1 The BBs leave no paint marks. How can you tell who has been hit?

3.1 Which airsoft gun is the best / most recommended?
3.2 Which gun / motor / battery has best power / range / accuracy?

a) Power
b) Range and Accuracy
c) Rate of Fire
d) Battery Size

• http://www.airsoft.org/'s (formerly known as Maccar26) thorough FAQ page
  
• Combat Zone's (A Swedish retailer) information page (in Swedish)
  
• Team Kaukopartio's Tech Files - A Beginner's Guide and some reviews (in Finnish)
  
  
  
  

Airsoft guns are low-powered air guns that are 1:1 scale models of real firearms. They fire 6mm plastic balls called BBs at a velocity low enough not to injure a person wearing safety goggles. This makes them safe for simulated wargames, often called skirmish games. The airsoft hobby originated in Japan and is not only about skirmishing as these models are so well made that they make for a fine collection of rare and interesting military weapons. This is especially true in Japan, where a civilian may not own a real firearm of any kind.

Airsoft guns are an attractive option in Europe, too, since many real firearms, readily available as airsoft models, are impossible or very expensive to obtain and carry with them the heavy responsiblility of securing them against theft and potentially fatal accidents. With many European countries passing more and more strict laws of gun control (which is not a totally bad thing, I think) airsoft models allow for a safe shooting hobby with the added benefit of having the targets shoot back for a little cinematic action and excitement.

Airsoft guns are not meant to be sold as 'pea-shooters' to kids, and doing so can result in serious problems as these guns have enough power to harm the human eye from a close range. In addition, the more expensive models are well-designed pieces of equipment that require careful handling and maintenace in order to work properly. Buying - or selling! - such an item to a person under 16 years of age should be considered highly irresponsible.

I think most people can agree nowadays that real violence and war are not optimal solutions to any problems, and that a real shooting war where people get killed is never a pleasant thing. But the question whether action games of simulated conflict, where nobody gets hurt, are bad for people, remains unanswered. Truth is, however, that such fictive or competetive conflict is and has always been a major part in the entertainment business of mankind: From medieval jousting tournaments to modern fencing, which is an olympic sport but also most definetely a form of simulated combat. Needless to say, so is boxing and many other fighting sports where people can and sometimes do get hurt. Computer and video games are filled with action and simulated violence, and hundreds of thousands of people go to the movies each year to watch Bruce Willis & co fight it out with the bad guys.

So how does re-enacting modern combat situations differ from these forms of popular entertainment? You be the judge - If it helps, you can think of airsoft as a video game with unsurpassed 3-D graphics, unlimited tactical options and a lot more exercise and fresh air.

For mainly skirmishing, a Marui electric is an optimal choice; they are effective in terms of range and rate of fire, easy to maintain and very reliable. Which one, is mostly a matter of taste, as they differ very little in terms of performance and durability. The MP5 series is very popular and include good all-around weapons with many optional accessories available. Of these, the A4 is perhaps the best in terms of battery size and ease of customizing and/or converting into the other variants. When it comes to realistic appearance and optimal performance the AUG and AK series are even better, but also more expensive - the AUGs are also surprisingly heavy, which is a slight disadvantage in pure skirmishing.

Of the gas guns, a word of warning is in order. The best blowbacks are very, very nice but a lot less reliable than the electrics, especially in colder weather. They also lack the sheer firepower of a 1000+ shot battery and an optional 200-600 shot skirmish clip or two. Also, there are bigger differences in overall quality between different gas guns than between the electrics: cheap gas guns usually break down more easily and may have clearly inferior performance. On the other hand, the best gas guns exceed the average stock electrics both in power, accuracy and rate of fire. So, if you want an exquisite model gun, go for the TMP or other high-end blowback - but unless you have an electric to back it up, you may be at a slight disadvantage in heavy-duty skirmishing.

The opinions in this table are based on my own experiences and on those learned from reliable sources but they are still mostly opinions.

Power, as defined by how much 'oomph' an electric gun can put behind the BB, depends mainly on three basic things: The strenght of the spring, the size of the piston cylinder and the lenght and tightness of the gun barrel. A stronger spring generates more power behind the piston. A larger cylinder holds more air which, if compressed with equal force will produce more pressure for the same-sized barrel. A tighter-bore barrel can use more of this pressure to drive the BB as less will leak around the projectile. A longer barrel will give, simplified, more distance for these forces to accelerate the BB.

These factors roughly determine the kinetic energy of the projectile as it leaves the gun barrel. This amount of energy represents the gun's energy output, called muzzle energy, which can be measured by measuring muzzle velocity - the speed of the projectile as it leaves the barrel. From the formula E_k=½mv² (where m equals the mass of the projectile and v the velocity) you can see, that this energy is directly proportionate to the mass (0.20 or 0.25g usually) of the BB and it's velocity squared. As the energy output of the gun remains more or less constant, a heavier BB will have less velocity but roughly the same amount of energy as a lighter BB when it leaves the gun barrel. The energy of the BB (how hard it will hit) at a certain range beyond that point, depends largely on the same factors that determine the maxium range.

Contrary to popular beliefs, larger (In terms of mAh) batteries or stronger motors have no effect whatsoever on the gun's energy output. Stronger motors can drive stronger springs but have no effect unless the spring is upgraded. Neither do the gears: high quality gears can better withstand the increased strain of being caught between a stronger spring and a stronger motor but when used with a normal spring, they just last even longer.

After leaving the barrel the BB is on its own. It has certain velocity (which in turn has a direction, but we don't want ot get into vectors here, do we?) and mass. On it's way to the target, it must face gravity and air resistance which both work against it. Air resistance starts to eat away a projectile's energy as soon as it leaves the barrel resulting in dropping velocity. Air resistance grows proprotionate to the velocity so it attacks faster BBs harder. Heavier BBs have an advantage here as they have more energy to spend fighting the drag for the same velocity: a BB that has less weight and higher velocity (but the same muzzle energy) must fight a significantly higher air resistance and thus it runs out of energy faster.

So, without gravity, the BB would simply fly in a straight line until all its energy were exhausted fighting the drag and then it would simply stop in mid-air, with heavier ones travelling furthest. With gravity tugging it down all the way, the flight path becomes a ballistic curve instead. So, overly simplified, the range of a gun is determined as the distance it's projectile can travel in the time it takes gravity to rudely pull it down. Here the speed is an advantage: with no forces to oppose it, the gravity will work equally fast on every object but the faster projectile will fly further in the same time. So, in a void with no air resistance but with normal gravity the fastest BB would fly furthest regardless of weight.

So both the speed and weight of the BB contribute to the range of the gun. Why, then, a heavier BBs seem to give better range? A lighter 0.12 BB will fly faster and but will also lose it's energy more rapidly to air resistance than a heavier projectile travelling more slowly. A slower projectile, on the other hand, will cover less distance before it gets pulled to the ground by gravity, but will have more energy left after the same amount of flighttime. Air resistance can be minimized by using high quality BBs that have smooth, even surface, but this is a minor point. To fight the gravity, airsoft designers came up with an ingenious device called Hop-Up.

The Hop-Up system puts a backspin on the BB so it will spin rapidly as it flies through the air. Surrounding air will travel faster on the upper surface as on this side the surfce is moving less fast against it, creating less drag. Under the BB, however the reverse is true: the air faces the combined speed of the BB and of the spinning surface thus inreasing air resistance. Now we have smooth, fast airflow on the upper surface and heavier drag on the lower surface, which is exactly what happens around a wing of an airplane. This is called Bernoulli effect and it produces a very useful force called 'lift'. This force, proportionate to the combined speeds of the projectile and of the backspin, tries to pull the BB upwards, against the gravity, which, in turn is a force proportionate to the weight of the BB. Occasionally, the lift will temporarily win, as is case when there is too high backspin / weight -ratio. This is why the light 0.12g BBs sometimes curve upwards when fired with too much Hop. One side-effect of Hop-Up is that it uses some of the gun's energy output by using friction to create the backspin - thus resulting in a slightly lower muzzle energy. The deal, however, is well worth it.

So, the range of an airsoft gun depends on the gun's energy output, the weight of the BB and the amount Hop Up. Our average issue Marui M4A1 gives an output of roughly 0.8 Joules. With a 0.12g BB, most of this would go to the speed, which, unfortunately would be rapidly eaten away by increased air resistance (remember, air resistance doesn't mind about weight, it's the speed that bothers it). A lighter BB is also much easily affected by crosswinds, wrongly adjusted Hop Up and intercepting foliage. Using a heavier 0.25g BB, we should get the same muzzle energy but, of course, lower velocity. With correctly adjusted Hop-Up, however, there is no rush as the lift will keep on fighting the downpull of gravity as long as the BB keeps spinning fast enough. Air resistance will, of course, put an end to this eventually, and the gravity will win. But a heavier BB will maintain its energy longer and thus gives more range and, as a bonus, more hitting power at any given range.

Accuracy depends on the same things as the range, plus a few other things. As we agreed above, a heavier BB will be less affected by crosswinds and freak occurrences like uneven drag caused by an uneven surface of the BB. A heavier (and thus slower) BB will, without Hop Up, also drop more at the same range (maybe resulting in hits to sensitive areas when your aim was on the chest). With correctly adjusted Hop Up, the flight path becomes more level, which greatly improves accuracy. Also, longer and tighter gun barrel, having already contributed to the accuracy through incrasing energy output, also makes for a weapon that is easier to aim more accurately. On the other hand and contrary to a popular belief, stronger motor or bigger battery have no direct effect on the range or accuracy.

Now, this is where the motor and battery qualities come into play. The newer Marui motors (EG700, EG1000) are a bit faster than the old EG560 but no by much. What makes them better is that they are stronger, i.e. they have more torque. To make them run faster and thus increase the rate of fire, one would have to increase the voltage beoynd the standard 8.4V which is common to all batteries regardless of their size (more of this later). Unfortunately, higher voltage might result in a blown fuse or even a burnt motor, so it is not recommended.

With all motors runnig with standard 8.4V batteries giving out roughly the same rate of fire, the safe thing to do in order to increase the rate of fire is to alter the transmission, i.e. the gearbox. Strangely enough, the oldest Marui mechabox, Mk 1 used in both FAMAS models, gives out the fastest rate of fire, which is just as well since the real-steel FAMAS also has relatively high rate of fire (close to 1000rpm). The downside is probably a lower torque transmission which would mean that the FAMAS is least likely to be able to handle a stiffer spring without other modifications.

There are also after-market gear sets available from Systema, which specifically alter the transmission to increase the rate of fire. This, combined with maybe slight increase in voltage (say, 9,6V), an EG1000 motor and no heavier than a 100M spring would give a significant increase in rate of fire and great overall performance. Not a cheap solution, though.

Battery size, often measured as mAh (milliamper-hours), does not affect the gun's performance in any way. What it does affect is the number of shots that can be fired before the battery runs out. As an analogy, let's think of a lake from which springs a river with a waterfall. The height of the waterfall determines its energy potential with which it could power, for example, a watermill. This height is analogous to the voltage of a battery - the higher the voltage, the faster the motor will run. That is, if there is enough water flowing: a small trickle of water would not run a mill no matter how high the waterfall.

The flow of electricity is measured by current, the unit of which is an Amper. The flow of the current depends on the width (and depth) of the river - or the resistance of an electric circuit. Now, an electric motor will draw a constant current depending on the qualities, mainly the strenght, of the motor. The energy pontential - the height of the waterfall - is the same for all Marui batteries - namely 8.4 Volts. What makes the difference between different battery Types, is the size of the 'lake': a smaller (and thus more compact) battery can sustain the same current for a shorter period of time before running out, like a smaller lake will dry out faster with a given amount of river flow draining it. A mightier river (a stronger motor) will drain a smaller lake (a battery) even faster, which is actually a small problem with the new M4A1.