The world's first 3-D printed bullets aren't anything to fear, according to the man who first tested them.

The 3-D printed shotgun slugs fired successfully out of a shotgun, but Jeff Heeszel, the man who shot them, said they were "some of the worst round's [he's] ever fired out of a shotgun."

Heeszel's popular YouTube channel, Taofledermaus, is known for featuring and grading the accuracy of odd ammunitions, such as silly putty and chocolate loaded into shotgun shells. Heeszel says the 3-D slugs performed worse than silly putty.

"They were lame to be honest with you. They were extremely lightweight, we had trouble keeping them flying straight," he says. "They tumbled around and as far as lethality, I don't think anyone would get too hurt by one of these."

The bullets were designed by a YouTube user known as ArtisanTony, who is working on a 3-D printed gun. He sent the bullets for Heeszel to test because Heeszel owns high-speed cameras that could be used to track their performance. The bullets weigh 0.4 ounces.

Last week, the Department of Justice ordered the man who created the world's first functioning 3-D printed gun to remove the blueprints from the Internet, but not before the plans made their way to the popular torrenting site The Pirate Bay. Since then, plans for "The Liberator" have been downloaded more than 100,000 times.

Heeszel says the bullets are nothing more than a "novelty" at this point.

"It's kind of like, why did the man climb the mountain? It's just because it was there kind of thing," he says. "I don't think the world needs to worry about 3-D printed bullets. You still need primers, powder and a standard shotgun shell to shoot it."