They are more dangerous because when used they can not be traced to anything.
You also do not know the metallurgy of the parts, which means nothing to morons
But you go on babbling
The “Ghost” Guns can be assembled with parts that not only meet but exceed the minimum safe standards for the weapon from the original manufacturer. So metallurgy is not an issue. The same parts can be used to repair or upgrade an existing weapon. You can even use original parts from manufacturers.
Let’s take an AR. The part that is the “ghost” is the lower receiver. These are essentially the same for all AR type weapons. You can fit a long range accuracy upper receiver to a very inexpensive lower and it will shoot without any trouble. It fits and fires no problem. It is one of the reasons the modular design of the AR is popular. You can customize it any number of ways to suit your needs and wants.
The only thing that needs to be matched carefully is the bolt and chamber. Those need to be customized one to another. Never use another bolt in your AR. Each Bolt needs to be mated to its own rifle chamber.
People change parts all the time otherwise. A different trigger or spring to adjust the way the rifle shoots. I personally prefer a target trigger. It is very light and not suitable for combat style shooting. If you pull my trigger you will find it fires before your nail starts to turn white. This is good for longer range accuracy. It is too risky for combat style events. If I was participating in combat style events I would swap the trigger out for a less sensitive one.
In a way. Weapons are like golf clubs. Each club has something it is really good at. There is no one size fits all golf club. Just as there is no one size fits all firearm. The AR I use has a MOA setup. This means less than one MOA of variance in each shot. That is less than an inch at 100 yards. Less than five inches at five hundred and so on.
Think of it like this. Cars. There are more than a dozen brands of cars. Each brand has many different models. Each model has many different options. You can order the car you want set up the way you want to suit your needs. Everyone does not get the same car. Some get sporty cars. Others get basic cars. If you need to haul things you might get a truck. If you want to carry kids and such you might get a minivan. Or you might get a minivan and convert it to carry a stretcher for an invalided family member. Which is right?
You research the brands and models. You decide what you want based upon your own criteria. You pick the car that is right for you. People do the same with firearms.
There are others who customize the car. They put different wheels and tires on. They change components under the hood or even replace the entire engine or transmission. Some will build their car from the frame up. Nothing under the body is they way the maker put it there.
People do that with lots of things. Wardrobes. Computers. Furniture. The list is endless. Is a souped up Mustang with racing seats and a five point harness inherently less safe than a stock mustang? No. It is the way the car is driven. The souped up car may be driven like granny was behind the wheel on the streets. While the stock mustang is driven by an idiot with one point left on his license.
And just like cars, there are illegal mods. Things you can’t do to your guns. A hand cranked Gatling gun is legal. Attach your black and decker drill to the crank and it is now illegal.