I would highly recommend that you do not make your own airsoft pellets. They might jam and or brake your gun.
Airsoft weapons do not fire real ammunition.
Yes.
In the magazine.
The bullets used in an Airsoft gun are BB's but an owner should make sure that pay attention.to the quality of BB's that they buy. If they are sure to buy the best BB's the gearbox components will be damaged and cause the owner to spend far more cash over the long haul.
First a clip is very different from a magazine. A magazine is something that the ammo is self-contained in. A clip a "string" of bullets in which you push the bullets into the gun. I do not think it is possible to make an airsoft magazine, but they are fairly cheap to buy. A clip is something that I do not think you can make either but they are also fairly cheap. The only guns that I know make a clip are the D-Boys Kar-98 (same with Marushin). Some M1 grands use a airsoft style "clip". All in all, it is not practical to make an airsoft mag or clip.
30-45.
Most airsoft guns have magazines that you put bbs into just like you put real bullets into a real gun's magazine
first by, telling them they are not real bullets, and you wont point at anyone in the face
I know at Academy Sports you have to be 18 years or older.
No they are Copper, Lead or Steel ball bearings. airsoft uses 6mm plastic BB
Yes, every airsoft gun can fire any gram of BB, although .12g BBs wont be that effective in a sniper, try .25g or even .3g.
probably not... the bb size has to be the same caliber as the bb gun. the airsoft bb is also made of plastic so it would probably shatter inside of the barrel because it is too light.