1883 Liberty V Nickel, What Kind Of Error?

Might be a slight clipped planchet that's obscured by the holder prong. Nice coin, but probably wouldn't add any value to have it attributed as such.

Very nice pictures.

That might be a faint Smith Effect on the reverse rim.

Is this a proof coin?

Sure. There are two main clues that a clipped planchet is real.

The first is the Blakesley Effect. When a planchet is missing enough metal in the clip, it will not pass through the rim upset mill properly. Every time the planchet rolls past the missing metal, the machine pressure falls, leading to a flattened area with no proper rim directly across from the clip.

This coin doesn't appear to show that. It probably isn't missing enough metal to cause a Blakesley effect (if it is even a clipped planchet at all).

The second clue is the Smith Effect. As the rim arrives at the missing clip area, the inside edge takes a curved shape towards the outer shape. It almost resembles a talon. This happens because there isn't enough metal to push into a complete rim during striking. The strike pressure causes the planchet metal to flow into the missing clip. A good example of the Smith effect:

http://goccf.com/t/435269

This coin might have a bit of Smith effect. I am no expert on mint errors, and certainly not vintage mint errors. But it does bear some visual similarities.

Got it, thanks for that.

It's not Proof, it's MS63 and thank you all for the info.