Corrected entry: There's no way anyone could cut off their hand with a knife the way Wormtail did. The only way they could do it is if they slowly sawed it off. Even if he raised the knife and swung it hard, there's no way it would work, the bone is way too strong. But Wormtail didn't even do that, he just placed the knife on his hand and moved it down. You couldn't even cut hair like that.
MikeH
14th Dec 2018
Harry Potter and the Goblet of Fire (2005)
Correction: He didn't cut through bone, he cut his wrist and the knife moved past the bones. If the force is strong enough and the knife sharp enough it's definitely possible to do this.
5th Mar 2015
Harry Potter and the Goblet of Fire (2005)
Corrected entry: When Frank is hit by the killing curse, he screams. The killing curse will kill you instantly, so he shouldn't have screamed.
Correction: He screams out of fear, before getting hit by the curse.
Correction: Wormtail is not just "anyone" though. He understood the importance of each of the ritual's steps and getting the potion done just right. He is following Voldemort's orders and instructions. Wormtail's dagger may have been magical, or a charm could have been placed on its finely edged blade to be swift in its tasks. Also, Wormtail was in a highly charged state of mind, which only intensified the force he used to "willingly" sacrifice his hand.
Super Grover ★
If I recall, it's described in the book as being a "quick flash of silver" indicating as you suggested the dagger has got some magical properties.
Ssiscool ★