Final answer:
The most common difference between rifles and shotguns is that rifles have a rifled barrel, causing the projectile to spin, while shotguns have a smoothbore barrel and fire multiple projectiles. Rifles are more accurate, especially at range. Recoil in rifles is based on Newton's third law of motion, and recoilless rifles have an open back design, but it's unsafe to stand behind them when fired.
Step-by-step explanation:
The most common difference between rifles and shotguns is that rifles have a rifled barrel, while shotguns have a smoothbore barrel. The grooves in the rifled barrel of a rifle cause the projectile to spin, giving it greater accuracy and stability over longer distances. Shotguns, on the other hand, typically fire multiple small projectiles called shot, which spread out over a wide area, making them more suitable for close-range targets. Because of the rifling, rifles can also be equipped with sights or scopes to enhance their long-range targeting capabilities. Therefore, another notable difference is that rifles are generally more accurate than shotguns, especially at range.
When an ordinary rifle is fired, it recoils or kicks backward due to Newton's third law of motion, which states that for every action, there is an equal and opposite reaction. The force of the expanding gas pressing forwards to propel the bullet out of the barrel also pushes backwards against the rifle. However, a recoilless rifle is designed with an open barrel at both ends, allowing some of the explosive force to escape out the back, which reduces the recoil felt by the shooter. Despite this design, it is not safe to stand close behind a recoilless rifle when it is fired, as the backward blast of escaping gas can be extremely dangerous.