Pistol is one.
Non adjustable blade sight.
Rifles are mostly 5.56 and handguns are 9mm. There are other calibers that are used, but those are the most common.
Rifles have bolt actions and I've never seen a bolt action on a shotgun or handgun
Yes, handguns have a serial number.
Iron sights are the most common an are sometimes interchangeable.
Very common. The .22 pistol is a very popular target and training firearm, and is a sizable part of the handgun market. There are about 10 in my collection.
Yes, handguns were used in WWI, and WWII.
Police detectives carry handguns. Glock, Sig and H&K are common brands.
As with MOST states in the US, Oregon does not require registration of ordinary rifles, shotguns or handguns. Common misconception.
Most historians believe handguns were first invented in the mid 1400s.
In most U.S. States, handguns don't require registration.
That's a very difficult question to answer because, of course, any caliber can kill. Smaller caliber handguns are fairly common in crime involving handguns because people believe large handguns are too diffucult to conceal. Most major police agencies in the U.S. use 9mm or .40 caliber handguns. It's also difficult to answer because information on caliber used in homicide and other crimes isn't readily available.