Caliban,The newbie faq provided by Allen pretty much sums it up. At one time gas operated guns dominated airsoft. Airsoft has come a long way, now we have assault electric guns, AEGs. I’m going to just run a few considerations you should take into account on your decision.
1) Gas guns these days, rather GBBs, are more of the back up weapon of choice. The reason being is these days GBBs are mainly handguns or small submachine guns like Mac-11s. Airsoft has pretty much stepped away from the days of gas operated ak47s and M16s. While there are up-to-date versions of these weapons such as the gas Colt M4A1 that KWC sells owning a gas operated gun is not cheap. For one it requires gas, not horribly expensive but it does add up over time. Secondly, gas operated weapons require a great deal more of maintenance. What it really adds up to is if you buy a gas-operated weapon you are investing a lot of time and money into the weapon, but nonetheless you should not disapprove of the firepower you receive.
2) AEGs are the current main technology of airsoft. After buying your gun and necessary components like battery and charger, your only expense is bbs and oil to grease it up here and there. The performance, while not up to par with a stock gas-operated rifle, it is still completive. An upgraded AEG can be much better then any gas operated weapon with ease. AEGs have a sort of vibration, not really a recoil affect, though there are some out there, but they come with a nice large price tag.
3) You can buy a gun and face protection and play. The more committed airsoft players buy army fatigues, tactical vets, pretty much anything you would want if you were going into real combat. Myself, I have a full SWAT type get up, from boots to gloves, everything. I also have a set of desert fatigues that I use for out in the desert. How much you commit, time and money, to airsoft is really up to you. I play on a daily bases so, as my girl friend puts it, I am over committed.
I hope I helped you at least a bit, I tend to ramble not totally forget what I am trying to answer.
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