There is no one answer- it depends on the rifle. They are generally less powerful than a full size battle rifle cartridge. The M16 rifle uses a 5.56mm bullet, the AK47 a 7.62mm bullet, etc.
Yes. Pump, Spring and PCP (PreCharged Pneumatic) are all more powerful than a C02 system
First, it is rifle, not riffle. Second, no, or we would shoot tanks with a rifle. Cannon are more powerful. Finally, depends on the rifle. I have a .22 rifle and a .44 magnum pistol. The pistol is far more powerful than the rifle. I also have a .22 pistol, and a 30-06 rifle. The rifle is far more powerful than the pistol (in THAT example).
No
If you mean .17 HMR and .22 LR, yes.
In 5.56x45, the CM901 and M16 are an even match. In 7.62x39 and 7.62x51, the CM901 is considerably more powerful.
Whether or not an air rifle is more powerful than a cross bow depends on the air rifle or cross bow. Generally a hunter's cross bow is more powerful than a child's bb gun. However, during the Napoleonic Wars, the Austrians had an extremely powerful repeating air rifle. It could shoot several hundred meters. Austrian solders armed with them could shoot Napoleon's solders from such a great distance that Napoleon's solders could do nothing about it. Eventually they ran out of bullets.
Depends on the application. If you mean power, the higher the caliber, the more powerful it is. for example, a .22 caliber rifle is much less powerful than a .50 caliber rifle.
if you mean as opposed to a musket the rifling inside the barrel causes the bullet to spin which makes much more powerful and accurate. as opposed to a pistol, smg, lmg, or sniper rifle, an assault rifle is usually about 6-8 pounds which makes it easier to maneuver than an lmg or sniper, but more powerful than a pistol or smg
No. The .243 is a larger calibre, and the parent case is the .308 Winchester, necked down to accept the smaller projectile. It's considerably more powerful than the .223.
No specific term of reference. There are semi auto pistols that fire rifle cartridges, and are much more powerful than standard pistols.
First, you will have to define what makes a rifle "best". The AK47 is the most common, but was replaced by the AK74 using a new cartridge. The M16 is newer than the AK47, but has longer range and better accuracy. FN, Galil, Steyr and dozens of other firms make very good rifles. There will always be different opinions, and no one answer.