you cant without some kind of technology but you can use a slow burning a balloon and home made gun powder.
No.
I have never seen nor heard of a revolver airsoft pistol with non reusable shells. You should have no problems reusing them.
Yes.
No, they can not, do not attempt to mix real ammunition in airsoft guns.
Simply refill them, yes.
No, a mortar is not a projectile. A mortar is a type of lightweight artillery used to launch explosive shells at a high angle to a target. The projectile refers to the actual shell or bomb that is fired from the mortar.
It depends on the reason why they are
Yes, airsoft shells are refillable, being made of hard plastic and a hole to insert bb's in.
yes
Some shells hold up to 15.
"Killed by a shell" typically refers to death caused by explosive artillery shells in warfare. These shells are designed to explode upon impact, causing extensive damage and casualties. It is a common cause of death in conflicts involving heavy artillery fire.
Most sports stores will have them. Wal-Mart might have them. But E-Bay I know has them.