Depends entirely on the game laws in YOUR state. Run a Google search for "hunting regulations (your state name)" and you should be able to read the legal firearms information.
A caliber of rifles commonly used to hunt deer and elk.
It depends on the gun and caliber but most semi-automatic rifles such as the Ruger .22 are legal to hunt with in California.
In the US, the two most popular deer rifles are the Winchester 94 and the Marlin 336, both in caliber 30-30. However, "best" is a matter of choice, and the area where you hunt. A bolt action rifle in a caliber legal for your state may be a good choice, and less expensive than the lever guns. I hunt with a muzzle loading rifle, and get to hunt 2 more weeks than the folks with modern rifles.
No. There are, however, .22 caliber shotshells made for rifles.
The term "squirrel gun" was used with muzzle loading rifles that were smaller caliber than deer rifles. There was no one set caliber, but many were in .32 caliber, where a deer rifle would be .50, .54 or larger.
I believe that a .270 caliber, .308, .30-30, and .243 caliber rifles are great calibers to hunt deer with. I think that a .30-06 is just a bit overkill, but sometimes i will use that. i use eather a .270 or a .308 most of the time when i hunt white tail deer
The 308 caliber guns are more expensive than 5.56 assault rifles.
These excellent rifles are made in Turkey.
Maybe. They may be used to take small game, but not deer. They may not be used to hunt migratory birds, such as dove, ducks, or geese. Semi-automatic rifles may not be used. So if you want to squirrel hunt with a bolt action .22, you should be legal.
Rifles are referred to by caliber. Shotguns are referred to by gauge.
Which model and what caliber
Yes