It is possible.
Any bullet that has a diameter of one half inch is a .50 caliber bullet. There are different .50 caliber bullets- my Hawken muzzle loading rifle shoots a .50 caliber lead bullet, but different from the .50 Browning Machine Gun (that is also used in the .50 Barret sniper rifle)
A .50 magnum has a muzzle velocity of about 420 meters per second (1480 feet per second). The time for a .50 caliber bullet to travel one mile at a constant speed of 1400feet per second is around four seconds. After four seconds, the bullet will have dropped around 256 feet. In reality, the bullet is slowed down due to air resistance, and takes longer to travel one mile (thus it drops further). Also note that in theory, the caliber of the bullet does not determine how far it drops after traveling one mile. The muzzle velocity is the key parameter in determining this.
To the ground.
In excess of one mile
Yes, it is possible for a bullet to fully penetrate one person and also strike another person.
the bigger the animal the bigger the caliber of rifle and the heavier the bullet i.e deer 150 grain bullet 243 caliber and up moose 30-06 180 grain and up for both
Yes
All of it is lethal. There is no one "magic" bullet.
Sorry- there are too many variables to give you a simple answer. Depends on which bullet, fired by which rifle, at which wood, at which distance, at what angle. Depends on civilian .223, or military 5.56mm. The military round at 25 yards will penetrate more than one dozen 3/4 inch thick pine boards when hitting at a 90 degree angle. That is more than 9 inches of wood.
No one. A standard .45 ACP bullet is about 230 grains. A .45 caliber bullet that only weighed 50 grains would merely be a very thin disk of lead.
It depends on several factors, the main one being the propellant charge.
A 40 caliber bullet can penetrate through one piece of standard drywall with ease, and can potentially pass through multiple layers depending on the angle of impact and the specific type of drywall used. However, it is always safer to assume that gunfire can pass through multiple layers of drywall and take appropriate safety precautions.