The legality of wide open triggers depends on the country or state where the firearm is being used or owned. Therefore, the answer to whether wide open triggers are legal or not is not straightforward and requires a detailed explanation.

First, it is important to understand what a wide open trigger is. A wide open trigger is a type of firearm trigger that allows a firearm to be fired with a light or no pressure on the trigger. This means that the slightest movement or touch can cause the firearm to discharge. Wide open triggers are sometimes referred to as “hair triggers” because of their sensitivity.
In the United States, the legality of wide open triggers is a complicated issue that varies from state to state. The National Firearms Act (NFA) regulates the sale and ownership of firearms in the United States. The NFA was enacted in 1934 and is still in effect today. The NFA defines certain types of firearms, including machine guns and short-barreled rifles, as illegal to own or possess without a special license.
However, the NFA does not specifically address the issue of wide open triggers. Instead, the legality of wide open triggers is determined by state law. Some states have laws that prohibit the sale or possession of wide open triggers, while others have no specific laws regarding their use.
In California, for example, the use of a wide open trigger is illegal. Under California law, a person who possesses or uses a firearm with a wide open trigger is guilty of a misdemeanor. Similarly, in New York, the use of a wide open trigger is illegal. New York state law defines a wide open trigger as any trigger that requires a pressure of less than four pounds to fire the gun. Possession of a firearm with a wide open trigger is considered a Class A misdemeanor in New York.
In other states, such as Texas, the use of a wide open trigger is legal. Texas has no specific laws regulating the use of wide open triggers, so it is legal to own and use them in that state. However, it is important to note that even in states where wide open triggers are legal, their use may still be restricted in certain circumstances. For example, some shooting ranges may prohibit the use of wide open triggers for safety reasons.
In other countries, the legality of wide open triggers may be different. In the United Kingdom, for example, wide open triggers are illegal. Under UK law, any firearm that can be discharged with less than two pounds of pressure on the trigger is considered a prohibited weapon. Possession of a firearm with a wide open trigger is punishable by up to ten years in prison.
Similarly, in Canada, wide open triggers are illegal. Canadian law prohibits the possession or use of a firearm with a trigger that can be adjusted to reduce the force required to discharge the firearm. Possession of such a firearm is considered a criminal offense and can result in imprisonment.
In conclusion, the legality of wide open triggers depends on the country or state where the firearm is being used or owned. In the United States, the legality of wide open triggers is determined by state law. Some states have laws that prohibit the use or possession of wide open triggers, while others have no specific laws regarding their use. In other countries, such as the United Kingdom and Canada, wide open triggers are illegal. It is important to research the laws in your particular jurisdiction before owning or using a firearm with a wide open trigger.