It means the primer is located at the rear center of the cartridge, unlike rimfire, which has the primer in the rim.
WCF or W.C.F. stands for Winchester Center Fire (Sometimes seen as Winchester Centre Fire). This differentiates a center fire cartridge (the firing primer is in the center of the cartridge base) from a rim fire cartridge (the firing primer is in the case rim).
Ready to fire
Winchester Center Fire.
Multiple barrels arranged around a common center, barrels turn around that center as they fire.
To make it ready to fire.
On a center fire gun, rounded tip. On a rimfire gun, the tip is shaped a bit like the tip of a screwdriver blade.
The bore of a gun relates to the diameter of the hole in the barrel - and in turn the diameter of the bullet the gun can fire.
You must go into detail on what you mean by "rapid fire" in order to get an answer.
If you mean an M16 rifle, it can fire several miles. If can fire accurately to about 500 meters.
nothing
A couple of thousand degrees F. It is the center of a very intense but brief fire.
You will have to tell us if they are loaded or empty, whether they are shotgun shells (and the gauge), rim fire or center fire and the caliber.