Ignites the powder.
Exactly what is says, a primer made for small rifle ammunition.
The primer
The .44 Magnum uses the standard Large Pistol primer.
I assume you mean the ammo components, i.e. Primer, Small Pistol; Primer, Shotgun. You can get these either from disassembling ammo of the same category (Sm. Pistol, Lg. Pistol, Sm. Rifle, Lg. Rifle, Shotgun, or .50 MG) or you can buy them from various vendors. The Gun Runners have it almost all the time.
It has a small amount of material that is sensitive to shock. When a firing pin strikes the primer, it ignites.
Small rifle
No. They are the wrong diameter, 45 you need large pistol/large rifle sized primer diameter. Also rifle primers are thicker and require a heavier primer strike that some pistols can not deliver. My Springfield XDM only intermittently can set off a small rifle primer when used to load 9mm.
Depends on the round.
Rifle primers are generally not reccommended for muzzle loading firearms- the flame is not large enough to reliably ignite black powder or Pyrodex. There are nipples that use a #209 shotgun primer, and even then, it is reccommended that you use a primer intended for black powder. Check with Dixie Gun works for a nipple that will fit your rifle.
It is the container for the propellant (gun powder) and a holder for the primer and the bullet. On firing, the case expands, gripping the walls of the chamber, and forms a gas tight seal.
Deff a sniper rifle
It is located on the rear of the cartridge. If it is a rimfire, such as .22 Long Rifle, it is in the folded rim of the cartridge. Larger cartridges, such as the 30-30, are centerfire, and the primer is located at the rear center of the cartridge.