[–] JacobJaredKenworthy 0 points 6 points 6 points (+6|-0) ago (edited ago)
An air rifle is any air-powered rifle. Most pellet guns are air rifles, but there are some pellet guns that are pistols. Pellet guns have rifled bores and are so named because they fire lead pellets of various calibers, although some can also fire round BBs.
A BB gun is an airgun that fires .177 caliber round balls. I don't think BB guns could be considered "air rifles" because BB guns are all smoothbore to my knowledge, not rifled.
[–] Niggardly_Jew 0 points 1 point 1 point (+1|-0) ago
Pneumatic weapons can be lethal! Although they have a generally longer reloading time, they are also usually much quieter.
[–] JacobJaredKenworthy 0 points 3 points 3 points (+3|-0) ago
BB guns usually do use springs to compress the air, but the actually propelling force comes from the compressed air.
Not all airguns are toys. Lewis and Clark used a .46 caliber Girandoni air rifle on their expedition. It's very lethal. The Austrian army also used the Girandoni.
[–] Tsilent_Tsunami 0 points 3 points 3 points (+3|-0) ago
https://www.youtube.com/watch?v=9KgWSDVCjzQ (2:54)
50 Caliber Air Rifle - This is the big brother of a bb gun. Note that it's NOT a firearm.