Don't know if it's made anymore, but it would probably be the .17/44 - a .17 projectile in a necked down .44 Magnum casing.
There are several different .17 caliber catridges- some rimfire, some centerfire.
There are any number of things NOT found in a centerfire rifle cartridge. However, what WILL be found is a centerfire primer, a cartridge case, powder and bullet.
what do you mean smallest ? smallest diameter bullet ? smallest case ? 5mm , or 22 high power, 17 rem , be specific .
The .45 caliber bullet is not used in a sniper rifle.
There are 22 caliber centerfire cartridges such as the .22 Hornet and others, but ordinary 22 cartridges (short, long, long rifle) are rimfire.
The correct size of the bullet that fits the rifle.
A rifle that shoots a .22 caliber bullet.
If you mean a .222 caliber rifle, this is a centerfire bottlenecked catridge. It fires a very small, very fast bullet, and is typically used for target and varmint shooting. It has no relation to the typical .22 rimfire, and is much more powerful.
If you're talking about the difference between a .22 short or long rifle and a .25 ACP, the .22 is a rimfire cartridge and the .25 is a centerfire. Also, the .25 is .03 of an inch larger in diamter.
It looks like if it is a centerfire caliber you can use it. So, yes you can use a .223 caliber rifle.
That would depend on the caliber, and type of bullet, the rifle uses.
Varies every couple of years. 30/06 probably