This is a video promotion of a website that sells plans for a home-built revolver. I like the concept, but this implementation has some flaws... one of which will land you in prison if you actually build this as presented, and get caught. And you will get caught if you are in the US and purchase these plans. We will start with that.
Here's the problem: in the USA, handguns must have rifling in the barrel. Possession of an unrifled handgun is a violation of the National Firearms Act and a felony. The penalty is ten years in prison and a ten thousand dollar fine. This law has been in effect since 1934.
There is a way to avoid that, and it involves registering the gun (before you build it) and paying a $200 tax. It takes many months, pretty close to a year in fact, to have your registration approved. I think it's safe to say that no one will be going to that much trouble and expense for a gun like this.
I mentioned above that if you purchase these plans and build one of these revolvers, you will get caught. Here's why: The guy who is selling these plans is very publicly violating NFA, if he is in the USA. While I don't have absolute proof that he has not rifled each (or any, for that matter) chamber of his cylinders, I really doubt that he has. For one thing, he doesn't mention rifling. For another, if you watch near the end of the video where he is shooting the revolvers, you can see that every bullet is tumbling. Each hole in the paper is oblong because the bullets are striking every way but dead-on. Since stabilization is the function of rifling, it's pretty obvious that these guns don't have any rifling. The Bureau of Alcohol, Tobacco, Firearms and Explosives is definitely aware of this guy; don't fool yourself that they're not. If he hasn't already heard from them, he will. And when he does, they will almost certainly seize a list of everyone who has bought his plans.
It is possible to legally build you own firearm from scratch (federally and in most states) if you are not prohibited from possessing firearms. But if you're gonna do it, make sure the gun you are building is legal, ok? I would make this one legal by attaching a rifled barrel (even a stubby, one inch long barrel) to the front. That would make it legal federally and in most states. I would also eliminate the screw attachment of the front and rear frame pieces, and instead cut the frame out of a single piece of steel or aluminum. You could still remove the base pin to remove the cylinder; that frame piece doesn't need to be removable.
I would delete the safety screw, too. It's not needed. Just leave one chamber unloaded, and rest the firing pin on that chamber. Or, if you really want a safety, make the base pin long enough to extend through the breech plate and block the hammer. You could either thread it or, better yet, make a catch for the front of the frame, with "safe" and "fire" notches in the base pin.