No, they can not, do not attempt to mix real ammunition in airsoft guns.
No
Shell-ejecting airsoft guns tend to eject their shells using a spring loaded system. once the bolt, or slide is drawn back after firing, the spring will force the spent shell out of the gun
dont they will wear away the gears and will jam your gun
No.
It all depends on the model your looking at. So, to make it simple, elaborate. My pump action M56A uses airsoft shotgun shells, that act as magazines. So in a real shotgun, when the shell of a shotgun is fired, the Shell ejects, and the bb's fire. In an airsoft shotgun, depending upon the model, a shell shotgun fires 1 or 3 bb's, and without ejecting the shell, you pump again, causing more pre-loaded bb's into the chamber. But in some Airsoft shotguns, they use Magazines. You insert the magazine into the underside of the gun, and when you re-pump, bb(s) load into the chamber. That would be the logical answer. You used the word "Have". Do i "have to use shells". There are magazine alternatives, and you can always do it the good old fashion manual loading method. You could "screw" the loading mechanism, and manually force the bb's into the chamber. Not recommended. Any more questions, email me.
No. Metal bb's will not work in airsoft guns.
it doesnt work
Yes
NO
There is no difference! A m16 or any other gun must be blowback to work. Are you talking about airsoft or something, it does not matter. So a real m16 is already blowback, cant change that! and if your talking about airsoft it does not matter
No
No. Paintball barrels are .68 caliber and have relatively huge threads compared to airsoft guns. Not only would they not fit, they would not work due to the large space between the barrel and the airsoft pellet.