Interestingly in the United States, you can buy a long gun at the age of 18, but have to wait until you're 21 to buy and carry a handgun. I'm going to be 21 in just a few months so this is no big deal for me. However, it really begs the question as to why such a law is necessary.
I suppose the main argument is that an individual's mental capacity and maturity level isn't high enough to handle a handgun without supervision until the age of 21, but there are several flaws with said argument. For instance, each person matures at a different age, therefore one person might be completely mature enough to own a handgun at 18, whereas another might not be until 22 (a year after the age limit). In addition, if the reason is that 18, 19 and 20 year olds are too immature to own a handgun, then why can they buy shotguns and rifles, which can be equally as deadly in the wrong hands?
The fact remains that this law only affects law abiding citizens. Only law abiding citizens follow the law, underage gangbangers in Chicago don't care about the law and obtain their weapons from illegal sources. Therefore if the argument is to prevent gangbangers from owning guns, then it is clearly a failure. In addition, the law prevents 18, 19 and 20 year olds from defending themselves and presumes that their lives are worthless and not worth preserving.
What do you think, should we lower the handgun age to 18?