OK
AEG? Systema
Well, spring airsoft guns use an internal spring to fire the ammo and by auto you could be referring to either Auto Electric Guns (AEG's) which are quite popular and my personal favorite. AEG's use a rechargeable battery to operate a motor which fires the ammo that way. Have fun.
Crossman Uzi
You will lose velocity
It depends, dose your your sniper have threds? Type airsoft sniper silencer on Google and you will get something.
Automatic Electric Gun - i.e. airsoft toys guns.
my Willy wonker aka mm nan
The 'M4 3181 AEG FPS-300 Electric Airsoft Rifle, M203 Spring Grenade Launcher' is a HOT airsoft rifle. Not only does it offer a high power electric machine gun that shoots full or semi auto, it also has a grenade launcher. It is priced around $90, not bad for a rifle and grenade launcher.
In airsoft guns, automatic electric gun. Battery powered airsoft, versus spring powered or gas powered.
Try airrattle.com, airsoftgi.com, or just ebay!
Yes, it is AEG proline which means it is a fully automatic electronic competition level airsoft.